An autonomous medical monitoring system: Validation on arrhythmia detection.

In this paper, we present a generic platform for autonomous medical monitoring and diagnostics. We validated the platform in the context of arrhythmia detection with publicly available databases. The big advantage of this platform is its capacity to deal with various types of physiological signals. Many pre-processing steps are performed to bring the input information into a uniform state that will be explored by a machine learning algorithm. Since this block plays a crucial role in the entire processing pipeline, three different methods were evaluated for detection and classification of anomalies. The results presented in this work are validated on cardiac beats, where the highest accuracy was obtained on the classification of normal beats (94%). On the other hand, atrial fibrillation and premature ventricular contraction beats were classified with an accuracy of 78%.

Functional outcome and patient satisfaction after flexor tenotomy for plantar ulcers of the toes.

Ulcers of the toes may cause a severe physical burden, especially in patients with diabetes, in whom they occur most frequently. Several treatments have been proposed for the underlying anatomical abnormalities, but they vary in effectiveness. We evaluated our results in using flexor tenotomy to treat ulcers with underlying flexible clawing of the toes. For 42 toes from 23 patients, 15 of whom were diabetic, all ulcers healed. The mean healing time was 4 weeks (range, 1-8 weeks), the mean follow-up was 11 months (range, 1-27 months), and one recurrence and one complication occurred. Postoperative American Orthopaedic Foot Ankle Society Midfoot scores were available for 15 patients: the mean was 77 (range, 43-100). The mean visual analogue scale (VAS) for patient satisfaction increased from 3.9 points (range, 0-10 points) preoperatively to 7.7 (range, 5-10 points) postoperatively. Flexor tenotomy is a simple treatment with low complications and recurrence rates and provides good-to-excellent functional outcomes in treating flexible clawing of the toes and the associated ulceration.

Laparoscopic correction of umbilical hernias using a transabdominal preperitoneal approach: results of a pilot study.

BACKGROUND: Laparoscopic repair of umbilical hernias is usually based on the open underlay procedure in which the mesh is placed intra-abdominally. To prevent complications such as adhesions, bowel obstruction and fistula formation we developed a new laparoscopic approach, placing the mesh in the preperitoneal space. METHODS: Our laparoscopic approach concerns a standardised procedure with introduction of three intra-abdominally placed trocars. The ventral abdominal wall is incised in a lengthwise manner approximately 5 cm from the umbilical defect, followed by development of the preperitoneal space, reposition of the umbilical peritoneal sac and placement and fixation of a Prolene mesh. The mesh is secured using transfascial Prolene sutures; the peritoneal defect is closed with a running Vicryl suture. Data on 17 patients with primary umbilical hernias laparoscopically operated on between April 2002 and March 2006 are presented. RESULTS: The 11 men and 6 women had a mean age of 57.8 years (range 37-91 years) and a mean body mass index (BMI) of 30.6 kg/m(2) (range 23.7-37.9 kg/m(2)). Mean hernia size was 1.95 cm (range 1-3 cm), average mesh size was 110 cm(2) (range 100-150 cm(2)). Mean operating time was 85.6 min (range 60-120 min). Mean hospital stay was 2.2 days (range 1-3 days). No major complications were seen. No recurrences were observed during a mean follow-up of 36.2 months (range 13-62 months). CONCLUSIONS: The preperitoneal laparoscopic technique for umbilical hernia repair combines the advantages of a laparoscopic, minimally invasive, approach, avoiding the potential complications related to intra-abdominal mesh position.

Hand assisted laparoscopic surgery of aortoiliac occlusive disease: initial results.

OBJECTIVES: Open aortobifemoral bypass grafting has been the procedure of choice for many years in patients with symptomatic aortoiliac occlusive disease (AIOD). Hand assisted laparoscopic surgery (HALS) for AIOD could have advantages like faster recovery, faster oral intake and shorter hospital stay compared to the conventional technique. We documented the results of patients who underwent HALS for AIOD in our hospitals. MATERIALS AND METHODS: from January 1999 to December 2002, 33 consecutive patients underwent HALS for AIOD. Peri- and postoperative results were prospectively registered. Three different laparoscopic approaches were applied: transperitoneal, retroperitoneal and apron approach. RESULTS: There were 23 males and 10 females, with a mean age of 59 years (range 39-85). The surgical technique applied was: transperitoneal: 22 patients, retroperitoneal: 7 patients, apron: 4 patients. Per-operative results (median) of the transperitoneal, retroperitoneal and apron approach are: operating time 240, 420 and 263 minutes, cross clamp time 32.5, 40 and 33.5 minutes, blood loss 1150, 2100 and 950 ml, respectively. Postoperatively oral intake was fully resumed in 3, 4.5 and 2 days after performing the transperitoneal, retroperitoneal and apron technique. During the ICU stay patients received artificial respiration for 0, 1 and 0 days, admission to the ICU was 0.5, 1 and 0.75 days for the transperitoneal, retroperitoneal and apron approach. Finally, hospital stay was 8, 12.5 and 7 days after the transperitoneal, retroperitoneal and apron approach. Four patients (12%) had a minor complication, 4 patients (12%) had a major complication; pneumonia with ARDS, sepsis, bypass occlusion and chylo-abdomen. No patients died. CONCLUSIONS: HALS for AIOD is a technically demanding operation with a long learning curve. All three approaches are feasible. In this series of patients, we feel the transperitoneal and apron approach have the most advantages because of the larger working space. Finally, randomized trials will determine if laparoscopic assisted or total laparoscopic aortoiliac surgery has the potential to reduce morbidity for the patient compared to the conventional technique.

A clearly visible endoscopic instrument shaft on the monitor facilitates hand-eye coordination.

BACKGROUND: Passing an instrument through a small incision alters the kinematics of the instrument, thus hampering hand-eye coordination. Nevertheless, the incision provides a stable, nearly invariant, point of rotation for instrument movements. Therefore, we set out to evaluate the effects of the altered kinematics on hand-eye coordination. In addition, we assessed the hypothesis that the hand-eye coordination of laparoscopic surgeons incorporates the incision as a point of reference. METHODS: Eight surgeons with experience in laparoscopy repeatedly performed a positioning task on a two-dimensional endoscopic manipulation simulator. Task time was measured. In the first experiment, normal endoscopic manipulation was compared to a condition in which the kinematic effects of the incision were compensated for. In the second experiment, the instrument shaft on the monitor was not visible during half of the trials, so that all visual information about the location of the incision was obscured. RESULTS: Task performance improved significantly when the kinematic effects of the incision were compensated for (p = 0.001). Task performance improved when the instrument shaft was clearly visible on the monitor (p <0.05). CONCLUSIONS: Compensating for the kinematic effects introduced by the incision improves hand-eye coordination. The results of this study indicate that the incision provides a point of reference for hand-eye coordination during endoscopic manipulation.

Biotransformation of 1,2-dibromopropane in rats into four mercapturic acid derivatives.

1,2-Dibromopropane was administered orally in doses of 50-350 mg/kg to male Wistar rats. Four mercapturic acids were identified in urine by GC/MS, viz. N-acetyl-S-(2-oxopropyl)-L-cysteine (I), N-acetyl-S-(2-hydroxypropyl)-L-cysteine (II), N-acetyl-S-(1-carboxyethyl)-L-cysteine (III), and N-acetyl-S-(2-bromo-2-propenyl)-L-cysteine (IV). Mercapturic acid IV was a minor metabolite which could only be measured at doses of 200 mg/kg or higher. In 24 hr, urinary excretion of mercapturic acids amounted to about 36% of the dose (11% I, 21% II, 4% III, 0.2% IV). No dose dependency was found up to the highest dose. A unified scheme is proposed for the metabolism of 1,2-dibromopropane in the rat, which accounts for the identified mercapturic acids. The role of direct glutathione conjugation in the route leading to the major metabolite II, presumably involving thiiranium ion formation, is discussed. This route probably is biologically not very important because of the absence of detectable activity of 1,2-dibromopropane toward glutathione S-transferases in vitro, the very low mutagenicity of 1,2-dibromopropane, and the high mutagenic activity of N-acetyl-S-(2-bromopropyl)-L-cysteine methyl ester which was studied as a model compound for direct conjugation.

Estimation of o,p'-DDD in plasma by gas-liquid chromatography.

A method is described for the estimation of o,p'-DDD in plasma. To 50 microl plasma, 0.2 ml acetone is added. The mixture is extracted with 2 ml n-heptane containing p,p'-DDD as an internal standard. Water is removed by adding desiccated sodium sulfate. The organic phase can be injected into a gas chromatograph equipped with an electron capture detector. The o,p'-DDD content of the sample can be read from a calibration curve. Recovery of o,p'-DDD added to plasma is over 93%. The same procedure can be used for the estimation of o,p'-DDE.