Continuous recording of intrarectal pressures during the second phase of labour: correlations with postpartum pelvic floor complaints. A biomechanical-clinical study.

INTRODUCTION AND HYPOTHESIS: We correlated intrarectal pressure parameter recordings during the second phase of labour in primiparous women with postpartum pelvic floor (PF) complaints to try to define a critical pressure threshold for the occurrence of permanent PF injury. METHODS: Using a microsystem device, the duration of bearing-down efforts, the area under the pressure curve and the peak pressure during bearing-down efforts were continuously recorded in 43 women with spontaneous delivery (group one) and in 17 women with forceps-assisted delivery (group two). PF complaints were assessed using ICS-validated questionnaires established before delivery and 14 ± 6 months after delivery. RESULTS: Postpartum PF complaints were not significantly different between the groups. The first and second phases of labour were longer in women of group two. The three parameters measured were not correlated with the baby's weight or mode of delivery. The duration of bearing-down efforts was correlated with difficulty voiding and lower abdominal discomfort in women of group one only. The area under the pressure curve was correlated with feeling of urgency to void, urge incontinence, drops escape, decreased frequency of orgasm and difficulties in reaching orgasm in women of group two only. Peak pressure values were not correlated with any PF dysfunction. CONCLUSIONS: Intrarectal pressure parameters during second phase of labour show no significant correlations with obstetric parameters, but were significantly correlated with some urinary and sexual PF complaints 14 months after spontaneous and forceps-assisted delivery with a higher incidence of significant correlations in women of group two with forceps-assisted delivery, probably because of the longer first and second phases of labour.

[The peripheral sexual response ... from urogynecology to sexology]. / La réponse sexuelle périphérique ... de l'urogynécologie à la sexologie.

The peripheral sexual response is achieved by the the Clitoro-Urethro-Vaginal Complex who is responsible of the transmission of the sensitive stimulation to the CNS where this information is modulated by the different cerebral areas. These latter will send this message to the peripheral sexual organs using efferent somatic and autonomic pathways able to induce vaso congestive response of clitoridal area with contractions of pelvic floor muscles. Muscles stretch injuries after obstetrical or surgical trauma can decrease the quality of the sexual peripheral response. These modifications of peripheral sexual response have to be evaluated with a specific questionnaire and pelvic floor clinical examination and recently, with a new microsystem device able to record continuously intra-vaginal pressure modifications.

Artificial muscle to wash blood out of fibrillating atrium: an alternative to lifelong anticoagulation.

The Atripump is a motorless, volume displacement pump based on artificial muscle technology that could reproduce the pump function of normal atrium. It could help prevent blood clots due to blood stagnation and eventually avoid anticoagulation therapy in atrial fibrillation (AF). An animal study has been designed to assess mechanical effects of this pump on fibrillating atrium. The Atripump is a dome shaped silicone coated nitinol actuator. A pacemaker like control unit drives the actuator. In five adult sheep, the right atrium (RA) was exposed and dome sutured onto the epicardium. Atrial fibrillation was induced using rapid epicardial pacing (600 beats/min). Ejection fraction of the RA was obtained with intracardiac ultrasound in baseline, AF and Atripump assisted AF conditions. The dome's contraction rate was 60/min with power supply of 12V, 400 mA for 200 ms and ran for 2 hours in total. Mean temperature on the RA was 39+/-1.5 degrees C. Right atrium ejection fraction was 31% in baseline conditions, 5% and 20% in AF and assisted AF, respectively. In two animals a thrombus appeared in the right appendix and washed out once the pump was turned on. The Atripump washes blood out the RA acting as an anticoagulant device. Possible clinical implications in patients with chronic AF are prevention of embolism of cardiac origin and avoidance of hemorrhagic complication due to chronic anticoagulation.

Totally implantable robot to treat chronic atrial fibrillation.

Chronic atrial fibrillation affects millions of people worldwide. Its surgical treatment often fails to restore the transport function of the atrium. This study first introduces the concept of an atrial assist device (AAD) to restore the pump function of the atrium. The AAD is developed to be totally implantable in the human body with a transcutaneous energy transfer system to recharge the implanted battery. The ADD consists of a motorless pump based on artificial muscle technology, positioned on the external surface of the atrium to compress it and restore its muscular activity. A bench model reproduces the function of a fibrillating atrium to assess the circulatory support that this pump can provide. Atripump (Nanopowers SA, Switzerland) is a dome-shaped silicone-coated nitinol actuator 5 mm high, sutured on the external surface of the atrium. A pacemaker-like control unit drives the actuator that compresses the atrium, providing the mechanical support to the blood circulation. Electrical characteristics: the system is composed of one actuator that needs a minimal tension of 15 V and has a maximum current of 1.5 A with a 50% duty cycle. The implantable rechargeable battery is made of a cell having the following specifications: nominal tension of a cell: 4.1 V, tension after 90% of discharge: 3.5 V, nominal capacity of a cell: 163 mA h. The bench model consists of an open circuit made of latex bladder 60 mm in diameter filled with water. The bladder is connected to a vertically positioned tube that is filled to different levels, reproducing changes in cardiac preload. The Atripump is placed on the outer surface of the bladder. Pressure, volume and temperature changes were recorded. The contraction rate was 1 Hz with a power supply of 12 V, 400 mA for 200 ms. Preload ranged from 15 to 21 cm H(2)O. Maximal silicone membrane temperature was 55 degrees C and maximal temperature of the liquid environment was 35 degrees C. The pump produced a maximal work of 16 x 10(-3) J. Maximal volume pumped was 492 ml min(-1). This artificial muscle pump is compact, follows the Starling law and reproduces the hemodynamic performances of a normal atrium. It could represent a new tool to restore the atrial kick in persistent atrial fibrillation.

Artificial muscles to restore transport function of diseased atria.

Surgical treatment of persistent atrial fibrillation often fails to restore the transport function of the atrium. This study first introduces the concept of an atrial assist device to restore the pump function of the atrium. A micro motorless pump based on artificial muscle technology, is positioned on the external surface of the atrium to compress it and restore its muscular activity. A bench model reproduces the function of fibrillating atrium to assess the circulatory support that this pump can provide. The Atripump is a dome shape silicone coated nitinol actuator mounted on a plastic ring. A pacemaker-like control unit drives the actuator, which compresses the atrium, providing the mechanical support to the blood circulation. The bench model consists of an open circuit made of latex bladder 60 mm in diameter filled with water. The Atripump is placed on the outer surface of the bladder. Pressure, volume, and temperature changes were recorded. The contraction rate was 1 Hz with power supply of 12 V, 400 mA for 200 milliseconds. Preload ranged from 15 to 21 cm H20. The pump produced a maximal work of 16 x 10(-3) J. Maximal volume pumped was 492 ml/min. This artificial muscle pump is compact, and reproduces the hemodynamic performances of normal atrium.

Atria assist device to restore transport function of fibrillating atrium.

OBJECTIVE: The Maze procedure can restore sinus rhythm in patients suffering from chronic atrial fibrillation but often fails to restore the mechanical function of the atrium, the so-called atrial kick and requires long-term anticoagulation most of the time. A micro motorless pump (Atripump) based on artificial muscle technology positioned on the external surface of the atrium could compress the heart chamber, restoring atrium transport function. A bench model reproducing the mechanical function of human atrium and human environment has been developed to assess the circulatory support that such a pump can provide. METHODS: Atripump (Nanopowers SA, Switzerland) is a dome-shape, silicone-coated nitinol actuator to be sutured on the external surface of the atrium. A pacemaker-like control unit drives the actuator and manages the external compression of the atrium. The bench model consists of an open circuit made of rubber bladder, 60 cc in volume, connected to a vertically positioned and scaled tube that is filled at different levels reproducing changes in cardiac pre-load and after-load. The pump was placed on the outer surface of the bladder and both were immersed in water having a constant temperature of 37 degrees C. Pressure, volume and temperature at the interface dome-bladder were recorded. RESULTS: Pump ran 24 h for three consecutive months. During the experiment, no technical failure occurred and the pressure and volume values were repeatable during the experience. Nitinol fatigue was assessed measuring the wire's electric resistance that remained 400+/-10 Omega/m. Contraction rate was 1 Hz with power supply of 12 V, 400 m and heating time of 300 ms. Pre-load ranged from 11 to 15 mmHg. When inserted in the bath at 37+/-0.5 degrees C, maximal temperature between silicone membrane and rubber bladder was 39 degrees C. Maximal volume pumped was 492 ml/min. CONCLUSIONS: This artificial muscle pump can reproduce the mechanical effect of a normal human atrium. It is compact, reliable and follows the Starling law. The surface temperature is in the physiologic range and it could represent a new tool to restore the atrial kick in persistent atrial fibrillation.