Donald R. Mullen

Bio: Donald R. Mullen is an academic researcher. The author has contributed to research in topics: Heat exchanger & Thermoelectric cooling. The author has an hindex of 1, co-authored 1 publications receiving 325 citations.

Active thermal control of ultrasound transducers

Abstract: An ultrasound transducer assembly having a housing, a transducer array mounted in the housing, and active cooling mechanism positioned adjacent to the transducer array for actively removing heat generated by the array by transport of heat energy from the affected site. The active cooling mechanism may comprise a heat exchanger including a closed loop circulating coolant system circulating coolant, or a single-pass flowed coolant, passing through the heat exchanger, a heat pipe, a thermoelectric cooler, an evaporative/condenser system, and/or a phase change material. One or more heat exchangers may be used having gas or liquid coolants flowing therethrough. The heat exchangers and coolant pumps may be located in various components of the transducer assembly, including the array housing, the connector assemblies or the ultrasound console.

Fluid-assisted medical devices, systems and methods

Abstract: Surgical devices for treating tissue are provided. Also provided are systems for treating tissue and methods of treating tissue. An exemplary surgical device has a handle, a fluid passage connectable to a fluid source, a tip portion and a distal end. The tip portion can simultaneously provide RF power and conductive fluid to tissue. The tip portion includes an electrode having a domed portion having a domed surface and a cylindrical portion having a cylindrical surface. The domed portion is located distal to the cylindrical portion and occupies at least a portion of the distal end of the surgical device. The device includes a fluid outlet opening in fluid communication with the fluid passage, the fluid outlet opening configured to provide the conductive fluid to a surface of the electrode proximal to the distal end surface of the surgical device.

Vibration sensitive ablation device and method

Abstract: An ablation apparatus including a maneuvering mechanism, a conductive element attached to the apparatus, a sensor attached to the apparatus and an output device in communication with the sensor is provided. The sensor senses vibration during the ablation procedure and sends a signal to the output device to reduce power to the conductive element.

Apparatus and method for creating, maintaining, and controlling a virtual electrode used for the ablation of tissue

Abstract: The present invention provides an apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current, such tissues including but not limited to liver, lung, cardiac, prostate, breast, and vascular tissues and neoplasms. An apparatus in accord with the present invention includes a supply of a conductive or electrolytic fluid to be provided to the patient, an alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode. A method in accord with the present invention includes delivering a conductive fluid to a predetermined tissue ablation site for a predetermined time period, applying a predetermined power level of radio frequency current to the tissue, monitoring at least one of several parameters, and adjusting either the applied power and/or the fluid flow in response to the measured parameters.

Device and method for determining tissue thickness and creating cardiac ablation lesions

Abstract: A tissue ablation device has a handle and an ablation head coupled to the handle. The ablation head has a first jaw, a second jaw, and an ablative element coupled to at least one of the first and second jaws. A thickness measurement device may be coupled to the ablation device to indicate the distance separating the first and second jaws. Further, a force measurement device may be coupled to the ablation device to measure the force being applied by the first and second jaws to a piece of tissue. Further, a strain measurement device may be coupled to the ablation device to indicate the strain resulting in a piece of tissue disposed between the first and second jaws when a stress is applied to the tissue.

Methods of using high intensity focused ultrasound to form an ablated tissue area containing a plurality of lesions

Abstract: A device and method for ablating tissue is disclosed comprising the steps of acquiring an anatomical image of a patient, correlating the image to the patient, guiding an ablating member within the patient while tracking the position of the ablating member in the patient, positioning the ablating member in a desired position to ablate tissue, emitting ablating energy from the ablating member to form an ablated tissue area and removing the ablating member from the patient.