Optimization of extra corporeal enteral prosthesis (ECEP) by selective aspiration of the digestive flow.

Reinfusion is a medical process which collects digestive flow from a proximal stoma to a distal one, in patient who had a post-operative double enteral stoma. This process avoids the risk of under nutrition and frees the patient from a Total Parenteral Nutrition to offset the digestive loss. Most of the previous ways of reinfusion first collect the digestive flow into a bag before instillation. We developed an ambulatory reinfusion pump (ECEP) which had the advantage to collect the digestive flow directly from the proximal stoma and to pump it to the distal one. However, the main risk of such a continuous pumping process is to create mucosae lesions by direct suction. The aim of this study is to up-grade our device by introducing a selective aspiration based on the arrival of digestive flow.

Performance evaluation of the extra corporeal enteral prosthesis (ECEP) vs a By-Pass.

Intestinal stoma constitutes a symptomatic treatment in a wide range of digestive diseases, such as rectal cancer, digestive traumatic perforation and inflammatory intestinal diseases. It affects a patient's life causing physiologic and social constraints. The stoma can lead to involution of the downstream digestive tissue, impairing his function in case of restored continuity. Some technical solutions have been developed in order to maintain intestinal continuity, reduce inflammatory risk and to increase patient's quality of life. In this paper, we describe a smart intestinal prosthesis equipped with a pump working as an intestinal segment and creating a bypass between the upstream and downstream intestinal sides. We also evaluate the performance the digestive prosthesis ECEP vs a simple digestive By-Pass.

Post-operative blood loss monitoring device: a new tool for nursing activities.

In most medical specialties, after surgery, it is usual to place a drain at the operative site level, in order to assist the blood flow-out if necessary. This drainage allows avoiding the formation of hematomas and contributes to tissues recovery. However, postoperative blood loss can lead to serious consequences. Also, it is necessary to continuously check the blood output volume in order to be able to intervene quickly in case of too significant losses. In daily clinical practice, this task is due to the nursing staff that periodically records the blood level inside the supple bag connected to the drain. However, this method is not accurate about the volume of lost blood and does not reflect the flow of losses which is an important parameter regarding the evolution of the patient setting. We have designed and developed a prototype of a blood loss monitoring device based on the continuous weight measurement of the blood bag connected to the drain. This device is fixed on the bed and is able to instantaneously alert the medical staff in case of abnormal blood flow-out.

Microwave thermochemotherapy in the treatment of the bladder carcinoma--electromagnetic and dielectric studies--clinical protocol.

Microwave thermotherapy is currently used in clinical routines for benign prostatic hyperplasia treatments. The temperature increase is obtained using an endocavitary microwave applicator placed in the prostatic urethra. This urethral applicator after a technical modification can be placed inside the bladder in order to potentiate the effects of the treatment by chemotherapy of vesical carcinoma. This paper deals with electromagnetic studies of this new endocavitary applicator. First of all, the experimental determination of the dielectric permittivities for the propagation domain characterization is achieved in order to be used in the electromagnetic model. Compared to experimental results, these simulations obtained by the finite-difference time-domain formalism allow us to determine the electromagnetic performance of this applicator. Finally, the in vivo study realized on anesthetized dogs to determine the therapeutic protocol associating chemotherapy and thermotherapy in the treatment of the bladder cancer is presented.

New 434 MHz interstitial hyperthermia system monitored by microwave radiometry: theoretical and experimental results.

A new complete microwave interstitial hyperthermia system monitored automatically by microwave radiometry and working at 434 MHz is described in this paper. This system, which includes a new radiometer with two internal temperature references, is detailed. All its characteristics for microwave heating and radiometry are presented. The new possibilities are shown through numerous experiments on acrylamide phantom and excised tissues, which have been carried out for different antennae implantation corresponding to the clinical situation. The clinic protocol, associate to the brachytherapy, imposes the use of semi-loop catheters. Coaxial antennae, inserted in these catheters, are not, therefore, positioned in a rectilinear manner but undergo a curve. So, models based on the FDTD formalism are developed to determine the theoretical power deposition. Owing to these models, the effects of this physical motive on radiation diagrams can be taken into account. The results of the power deposition are presented for two antennae. Thermal patterns can then be determined by the solution of the bioheat-transfer equation in the steady state. Also, the comparison of the results given by the new interstitial hyperthermia system with those obtained with the previous 915 MHz one shows an improvement of the thermal performances.

[Study of the synergy of microwave hyperthermia/intravesical chemotherapy in the prevention of recurrences of superficial tumors of the bladder]. / Etude de la synergie hyperthermie micro-onde/chimiothérapie intravésicale dans la prévention des récidives des tumeurs superficielles de vessie.

OBJECTIVES: Preliminary clinical studies of the combination of hyperthermia and intravesical chemotherapy indicated very encouraging results in favour of multidisciplinary treatment of recurrent superficial bladder tumours. The authors studied the in vitro and early in vivo effects of this treatment. MATERIAL AND METHODS: An intravesical catheter equipped with a microwave antenna was used for hyperthermia in vivo in dogs. The temperature was controlled by two intravesical thermocouples and 4 transducers on the bladder wall. 0, 40 or 80 mg of mitomycin were instilled in 60 ml of physiological saline. Dogs were sacrificed after each one-hour session, and histological intravesical lesions were defined as grade 0, 1 or 2 corresponding to absence of lesions, or the presence of inflammatory lesions or urothelial lesions, respectively. In vitro, the first step consisted of creation of an immortalized tumour cell line from a grade II bladder papilloma. This HVT 196 cell line was incubated between 37 degrees C and 44 degrees C with increasing mitomycin concentrations of 0 to 10 micrograms per ml. The cytotoxicity was measured by the MTT quantitative colorimetric method. RESULTS: In vivo, in 8 dogs, histological analysis of the comparative cytotoxicity of the various treatments confirmed the synergistic effect of heat and mitomycin C. In dogs treated at 45 degrees C, marked urothelial lesions were observed, regardless of the mitomycin C concentration. The in vitro comparative toxicity study on our cell line showed a much more intense cytotoxic effect with combined treatment than with cytostatic treatment alone. Expressed as the percentage of cytotoxicity compared to a control cell pool for a concentration of 1 microgram per ml. the temperature rise of the medium between 37 degrees C and 44 degrees C was accompanied by a cytotoxic effect of 8.4% and 98.41% respectively. CONCLUSION: A possible clinical application is potentiation of the action of mitomycin C by hyperthermia in the prevention of recurrent superficial bladder tumours, achieving increased efficacy and/or a decreased number of instillations.

Study of the effects of thermotherapy in benign prostatic hypertrophy.

UNLABELLED: Prostatic transurethral thermotherapy was evaluated clinically using the Prostcare microwave system of the Bruker Company, which uses a microwave radiometer to measure and control intraprostatic temperature. OBJECTIVES: The aim of our study was to evaluate the immediate histological lesions induced in the prostatic tissue depending on the temperatures delivered to the prostate; the histological changes when adenectomy is carried out after thermotherapy, and the endoscopic appearance of the prostatic fossa 48 h, and 1, 2, 3 and 6 months after thermotherapy. METHODS: Our study was divided into three stages: in the first stage, we conducted thermotherapy in 10 patients in whom suprapubic adenectomy was indicated. During thermotherapy, a multipoint fiber-optic receptor and two thermocouples were implanted into the prostage gland at a distance of 5-15 mm from the urethra. Adenectomy was carried out 10 min after thermotherapy; the second stage of our study concerned the changes seen over time. We heated adenomas using the same protocol and carried out adenectomy 24, 48, 72 h, and 1 week, 6 weeks and 3 months after thermotherapy, and lastly, we studied the endoscopic appearance after a single heating-session of 30 min by endoscopic controls at different times after thermotherapy (48 h, 1, 2, 3 and 6 months after thermotherapy). RESULTS: Macroscopic appearance: necrotic lesions measured 30 mm in length on average. Necrosis was roughly circumferential. Immediate histological aspect: in all cases, histological examination showed coagulation necrosis with periurethral thromboses. Histological changes: at 8 days, necrosis intensity was maximal and histological structures were difficult to identify. Endoscopic appearance: 3 months after thermotherapy, the typical endoscopic appearance was a large periurethral cavity. There was a sharp demarcation between untreated areas and cicatricial tissue. CONCLUSION: The efficacy of thermotherapy depends on the radiometric temperature, which should reach 47 degrees C (i.e. a temperature of 55-65 degrees C delivered to the prostate), and a rapid increase in temperature, i.e. in the power applied, which should reach the thermal radiometric level of 47 degrees C in 5 min. As soon as necrosis is obtained, the power is automatically reduced. Using this protocol, heating proves effective in 30 min.

915 MHz microwave interstitial hyperthermia. Part III: Phase II clinical results.

From October 1989 to October 1991, 16 patients (17 tumours) with locally advanced carcinomas of the oral tongue and eight patients with second carcinomas of the base of tongue in previously irradiated areas, have been treated by means of an interstitial hyperthermia-brachytherapy combination in a phase II clinical trial. Each miniature microwave antenna of our hyperthermia system, called HIMCAR, is used both for heating and for thermal measurements by microwave radiometry at 3 and 9 GHz (see Part I). Among these 25 lesions (21 T2, 4 T3), 21 showed a complete response (15/17 locally advanced carcinomas and 6/8 second carcinomas in previously irradiated areas). The toxicity was not severe (less than 10%). A French multicentre phase III study is now under way.

Robotized scanning laser handpiece for the treatment of port wine stains and other angiodysplasias.

Port wine stains are currently treated by the argon laser with the "point-by-point" technique, or the "painting technique." In both cases, the quality of the results depends greatly on the dermatologist's experience. Furthermore, the first technique is slow, and the second is painful and requires anesthesia. Therefore, we have decided to design a robotized system with the following specifications: easy, fast, non-painful treatment giving a homogeneous and reproducible blanching. The system is made of a handpiece with the scanning mechanism and a control box with the microprocessor. The system is independent of the laser (no electrical connection) and has its own power meter. The deposit of energy was optimized in function of heat diffusion in the skin. Over a 12-month period, 123 patients were treated with the robotized handpiece. The treatment modalities and the results conformed to the above-mentioned specifications. Hypertrophic scars were not reported. Therefore, we think that this system will be an interesting tool for the laser treatment of port wine stains and other cutaneous angiodysplasias.

Development of controlled Nd:YAG laser for medical applications.

Several medical fields are concerned with applications of thermal lasers such as neodymium-doped, yttrium aluminum garnet (Nd:YAG), argon, and CO2. However, quantification of the necrotic volume of Nd:YAG laser-induced damage is not possible at the time of treatment. Mathematic models and feedback control can help to optimize Nd:YAG laser treatments. We therefore formulated mathematic models for coagulation processes and developed an intelligent Nd:YAG laser system with closed-loop feedback control. Surface temperature evolution proved to be valuable data for real-time control of coagulation and ablation. Infrared thermometry provided the noncontact measurement of temperature. A computer stored the temperature data calculated by the mathematic model. Deviations of surface temperature during the treatment beyond established tolerances causes the Nd:YAG laser system to adjust the laser power automatically.

[Processing of cephalometry: Delaire's architectural and structural analysis]. / Traitement de la céphalométrie. Application à l'analyse architecturale et structurale de Delaire.

This work purpose a performing system for the Cephalometry: Cephor a software for Delaire's analysis. From a radiography, we draw outlines on graphic tablet. Following in a short time, we obtain results: precise diagnosis permitting to establish a care plan. This care plan is indicated on the screen where we can simulate correction from a choised therapeutic (osteotomy for example). Moreover, this soft ware allows to survey numerically and graphically a treatment, allows to use others methods (Tweed, Ricketts, Steiner). Technological advantages rest on a hard gain of time and a precision gain. The large handiness of this system allows reproducible measures easily. Therefore, we own with this software an improvement and a performing system.