A redundant temperature monitoring system and method for an electrosurgical system are provided. The temperature monitoring circuit includes at least one temperature sensor for sensing a temperature at a measuring point, a first temperature measurement circuit coupled to the at least one temperature sensor for generating a first temperature value, a second temperature measurement circuit coupled to the at least one temperature sensor for generating a second temperature value, and a control circuit for determining a difference between the first and second temperature values and for comparing the difference to a first predetermined threshold. If the difference is greater than the first predetermined threshold, the control circuit generates a warning signal. If the difference is greater than a second predetermined threshold, the control circuit generates an alarm signal and/or shuts down a power source of the electrosurgical system.

Redundant temperature monitoring in electrosurgical systems for safety mitigation

An ultrasonic surgical instrument is presented including an ultrasonic transmission member having a proximal end and a distal end, and a handle member located at the proximal end of the transmission member. The ultrasonic surgical instrument also includes an end effector assembly located at the distal end of the transmission member. The end effector assembly includes a sensing mechanism for sensing load variations on tissue based on mechanical vibrations detected on one or more portions of the surgical instrument, the mechanical vibrations sensed by a laser interferometer.

Methods for ultrasonic tissue sensing and feedback

A system and method for heat ablation of tissue in which energy is sequentially applied to at least two electrodes inserted into tissue. The system is comprised of a radiofrequency (RF) source for supplying RF energy, at least two electrodes configured to apply RF energy to tissue, at least one return electrode for returning the RF energy to the RF source, and a controller configured to sequentially apply the RF energy to each of the at least two electrodes. The sequential delivery of energy is determined by the measured current and voltage, the calculated impedance at each of the electrodes and the timing for each electrode. An internal load may be activated with the previously activated channel and remain on until the next channel is activated to avoid the generator from having an open circuit.

Electrosurgical system employing multiple electrodes and method thereof

An apparatus and method are provided for precisely isolating a target lesion in a patient's body tissue, resulting in a high likelihood of “clean” margins about the lesion when it is removed for diagnosis and/or therapy. This approach advantageously will often result in the ability to both diagnose and treat a malignant lesion with only a single percutaneous procedure, with no follow-up percutaneous or surgical procedure required, while minimizing the risk of migration of possibly cancerous cells from the lesion to surrounding tissue or the bloodstream. In particular, the apparatus comprises a biopsy instrument having a distal end adapted for entry into the patient's body, a longitudinal shaft, and a cutting element disposed along the shaft. The cutting element is actuatable between a radially retracted position and a radially extended position. Advantageously, the instrument is rotatable about its axis in the radially extended position to isolate a desired tissue specimen from surrounding tissue by defining a peripheral margin about the tissue specimen. Once the tissue specimen is isolated, it may be segmented by further manipulation of the cutting element, after which the tissue segments are preferably individually removed from the patient's body through a cannula or the like. Alternatively, the specimen may be encapsulated and removed as an intact piece.

Breast biopsy system and methods

A novel fiber comprising a substantially homogeneous mixture of a hydrophilic polymer and a polymer which is at least weakly hydrophobic is disclosed. The fiber optionally contains a pH adjusting compound. A method of making the fiber comprises electrospinning fibers of the substantially homogeneous polymer solution. A method of treating a wound or other area of a patient requiring protection from contamination comprises electrospinning the substantially homogeneous polymer solution to form a dressing. An apparatus for electrospinning a wound dressing is disclosed. A medical dressing comprising at least one fiber electrospun from a polymer, wherein the dressing has a water vapor flux at least ten fold greater than that of solid film barrier dressings, and an air flow resistance of less than 5 X 109 m-1.

Electrospun fibers and an apparatus therefor

A polymerized microemulsion pressure sensitive adhesive composition is described. The composition has peel adhesion of at least 3 Newtons/100 mm as measured according to a PSTC-1 Test. The composition preferably has a bicontinuous structure of a continuous phase of a hydrophobic pressure sensitive adhesive polymer and a continuous phase of a hydrophilic polymer. The bulk properties of both polymers are retained in the bicontinuous structure. The composition is prepared from a microemulsion comprising a free-radically ethylenically unsaturated polar amphiphilic or hydrophilic monomer or oligomer in the aqueous phase, a free-radically ethylenically unsaturated hydrophobic monomer, having a glass transition temperature suitable for forming a pressure sensitive adhesive, in the oil phase, water, and surfactant. Uses for the pressure sensitive adhesive composition include biomedical articles, such as biomedical electrodes, medical skin coverings, and pharmaceutical delivery devices, and industrial articles, such as zinc/adhesive tapes used for cathodic protection of rebars embedded in concrete.

Polymerized microemulsion pressure sensitive adhesive compositions and methods of preparing and using same

Adhesive (I) consists of an ion-conducting, hydrophilic, pressure-sensitive, adhesive hydrogel (II) and a crosslinked poly(N-vinyllactam) (III). Pref., (III) is used in amt. giving low electrical impedance and ensuring adhesion and the cohesion of (II) when (I) is used in the presence of body fluids of the skin, which tend to soften (II). (II) consists of (a) partly neutralised acrylic acid homo- or copolymer, copoly(N-vinyl lactam) and a polyethylenically unsatd. cpd., copoly(N-vinyl lactam) and a carboxylic acid or an interpenetrating polymer network of a hydrophilic crosslinked polymer of a water-soluble monomer and a hydrophilic polymer, which is not crosslinked; (b) a source of moisture; and (c) water. USE/ADVANTAGE - (I) is claimed for use in electrodes, i.e., bio-electrodes, which are attached to skin of a nipple and connected to diagnostic, therapeutic or electro-surgical instruments. It has low impedance (claimed). It maintains its mechanical properties when water and moisture is absorbed from the skin.

Adhesive comprising hydrogel and crosslinked polyvinyl:lactam - is used in electrodes for biomedical application providing low impedance and good mechanical properties when water and/or moisture is absorbed from skin

A two-phase composite of ionically-conductive pressure-sensitive adhesive, biomedical electrodes using the composite and methods of preparing the composite and the electrode are disclosed. The continuous phase is a hydrophilic, solid state pressure-sensitive adhesive composition ionically-conductive regardless of an amount of water present in the composition. The discontinuous phase are domains of a hydrophobic pressure-sensitive adhesive which enhances adhesion of the composite to mammalian skin while maintaining acceptable alternating current impedance of the composite.

Two-phase composites of ionically-conductive pressure-sensitive adhesive, biomedical electrodes using the composites, and methods of preparing the composite and the biomedical electrodes

The present invention discloses a low impedance, water-absorbing, ionically-conductive, hydrophilic pressure sensitive adhesive composition comprising an ionically-conductive, hydrophilic, pressure sensitive adhesive hydrogel and crosslinked poly(N-vinyl lactam) in an amount sufficient to retain low electrical impedance and maintain hydrogel adhesion and cohesion during use of the composition in the presence of water and other moisture tending to plasticize the hydrogel. Crosslinked homopolymers and copolymers of poly(N-vinyl pyrrolidone) having Swelling Capacity of at least 15 milliliters of water per gram of poly(N-vinyl pyrrolidone) are preferred. Adhesion values upon removal from mammalian skin after about four hours of adhesion are not greater than initial adhesion removal values, demonstrating ease of removal of electrodes of the present invention from skin.

Low impedance pressure sensitive adhesive composition and biomedical electrodes using same

A hydrophilic, pressure-sensitive adhesive composition prepared by irradiating solid poly(N-vinyl lactam) with ionizing radiation to crosslink the poly(N-vinyl lactam) and thereafter mixing the radiation-crosslinked poly(N-vinyl lactam) with essentially unirradiated plasticizer in an amount sufficient to form a cohesive, pressure-sensitive adhesive composition. The composition is useful as a biomedical adhesive for transmitting or receiving electrical signals as a component (14) of a biomedical electrode (10).

Rosa Uy

Papers

Polymerized microemulsion pressure sensitive adhesive compositions and methods of preparing and using same

Adhesive comprising hydrogel and crosslinked polyvinyl:lactam - is used in electrodes for biomedical application providing low impedance and good mechanical properties when water and/or moisture is absorbed from skin

Two-phase composites of ionically-conductive pressure-sensitive adhesive, biomedical electrodes using the composites, and methods of preparing the composite and the biomedical electrodes

Low impedance pressure sensitive adhesive composition and biomedical electrodes using same

Pressure-sensitive poly(n-vinyl lactam) adhesive composition and method for producing and using same