This invention is an optically activated transducer for generating acoustic vibrations in a biological medium. The transducer is located at the end of a fiber optic which may be located within a catheter. Energy for operating the transducer is provided optically by laser light transmitted through the fiber optic to the transducer. Pulsed laser light is absorbed in the working fluid of the transducer to generate a thermal pressure and consequent adiabatic expansion of the transducer head such that it does work against the ambient medium. The transducer returns to its original state by a process of thermal cooling. The motion of the transducer within the ambient medium couples acoustic energy into the medium. By pulsing the laser at a high repetition rate (which may vary from CW to 100 kHz) an ultrasonic radiation field can be established locally in the medium. This method of producing ultrasonic vibrations can be used in vivo for the treatment of stroke-related conditions in humans, particularly for dissolving thrombus. The catheter may also incorporate anti-thrombolytic drug treatments as an adjunct therapy and it may be operated in conjunction with ultrasonic detection equipment for imaging and feedback control.

Opto-acoustic transducer for medical applications

A method is described for reducing the total emissions during cold starts from an engine burning a hydrocarbon fuel and having an afterburner arranged upstream of a catalytic converter. The method comprises the steps of: (i) adding an excess of fuel to the engine combustible charge and adding air to the engine exhaust gases immediately after the engine has first fired to assure the presence in the exhaust/air mixture of sufficient concentrations of hydrogen and oxygen to permit the resulting exhaust/air mixture to be ignitiable and to burn with a steady flame in the afterburner while the latter is at a temperature close to the ambient temperature, and (ii) igniting the exhaust/air mixture in the afterburner immediately after the engine has first fired. In the preferred embodiment of the invention, the excess fuel and/or the additional air are regulated after ignition has occurred in the afterburner to maintain a steady flame in the afterburner until at least part of the matrix of the catalytic converter has reached its light off temperature.

Operation of an internal combustion engine

A physical quantity detecting apparatus comprises at least one optical fiber, at least one light emitting means for emitting an incident light beam on the optical fiber, at least one light receiving means for detecting an outgoing light beam from the optical fiber, physical quantity applied position information generating means for providing information indicative of a position of a portion at which a physical quantity is applied to the optical fiber, and operation means for receiving signals from the light receiving means and physical quantities applied position information generating means and calculating a change with time in physical quantity at respective positions on the optical fiber

Physical quantity detecting apparatus and internal combustion engine control apparatus each utilizing optical fiber.

A device for detecting a pressure in a combustion chamber comprises a combustion pressure sensor (7) arranged in a cylinder head gasket (2) so that a pressure detecting surface (108) of the sensor is disposed substantially in parallel to a surface of a cylinder head (3) or a cylinder block (4), and a pressure inlet (11) is provided above the pressure detecting surface to introduce the combustion pressure to the pressure detecting surface. Due to the position of the pressure inlet above the pressure detecting surface, the tightening force of cylinder head bolts is not applied to the pressure detecting surface of the sensor, and thus the reliability of the pressure detection is improved.

Device for detecting combustion pressure of an internal combustion engine

An exhaust system of an internal-combustion engine ( 1 ) having an exhaust gas purification arrangement ( 3, 5 ) as well as a storage container ( 8 ) which can be evacuated and into which at least a portion of the internal-combustion engine exhaust gas flow can be introduced for a defined time period, particularly after a start of the internal-combustion engine. In addition to a stop valve ( 10 ), which maintains the vacuum in the storage container when the internal-combustion engine is stopped, a vacuum pump ( 18 ) is provided for evacuating the storage container. A stop flap ( 6 ) is provided in the exhaust system downstream of the exhaust gas purification arrangement. In a branch pipe ( 7 ) guiding the internal-combustion engine exhaust gas flow to the storage container ( 8 ), a control valve ( 9 ) may be provided for controlling the flow of exhaust gas to the storage container. In addition, the exhaust system may have a double-walled construction in areas, so that two essentially coaxially extending exhaust pipes exist, in which by way of the first, preferably interior exhaust pipe, the exhaust gas is guided away from the internal-combustion engine and, by way of the second, preferably exterior exhaust pipe, the exhaust gas is guided to the storage container.

Exhaust system of an internal-combustion engine having a storage volume

Purification of IC engine exhaust gases, provided with controlled buffer storage for gases during initial cold start-up. IC piston engine (10), with inlet manifold (12), butterfly throttle (14), and exhaust manifold (16) discharging into exhaust pipe (18) is provided with 3-way catalytic converter (20). A lambda probe (oxygen analyser) (22) is fitted into exhaust pipe (18), and provides a control signal to the fuel/air proportioning unit. Downstream of (22) the exhaust pipe branches (26) to a buffer vessel(28); the junction is fitted with an electro-magnetic actuated flap valve (30), above to close off either the buffer or exhaust discharge to the catalyst chamber. Buffer vessel (28) also connects into the inlet manifold (12). Buffer inlet line (26) includes a pump (34) and a non-return valve (36); a further non-return valve (38) is fitted between buffer vessel (28) and inlet manifold (12). The catalyst (20) and probe (22) each have electric resistance heaters; buffer vessel (28) has a pressure sensor (50). On completion of the ignition circuit, controller (40) decides if cold-start conditions apply (e.g. engine below 20 deg C), and if so, energises pump (34), and the resistance heaters, and closes the exhaust line via valve (30). In this way exhaust gates are contained for a few seconds, until a pre set pressure is attained, and then recycled to the engine inlet manifold. The now hot exhaust gases can be diverted to the catalyst chamber (20) at a temp. allowing effective oxidn.. ADVANTAGE - Avoids discharge or rich, unburned fuel gases to atmos. during cold start-up before catalyst becomes active.

Controlled IC exhaust gas buffer and recycle system - improving cold start=up efficiency of catalytic converters using an engine management device

An arrangement for measuring the pressure in the combustion chamber of an ic engine (1) has a pressure transducer connected to a measurement chamber (12) The latter is formed in a gap between the cylinder head (3) and the cylinder block (2) A measurement chamber wall (13) on the cylinder side forms a direct transfer wall and the boundary to the cylinder vol or combustion chamber (7) in the region of the cylinder wall USE/ADVANTAGE - Combustion chamber pressure is measured directly without influence of vibrations in engine housing parts

Pressure measurer for IC engine combustion chamber - has measurement chamber in gap between cylinder head and block for measurement free of influence from vibrating parts

The invention discloses automatic adaptation of spark timing in dynamic processes for a spark-ignition internal combution engine whereby, in a dynamic process, dynamic spark timing retardation values DELTA alpha Z1 are stored in an engine speed characteristic curve and added to a predetermined spark timing value alpha V in order to retard the spark timing. After a waiting time tW, the spark timing is advanced again to the predetermined value alpha V. The stored dynamic spark retardation values DELTA alpha Z1 can be varied in a kind of learning process. If a combustion with pinking occurs during an observation time tB, a dynamic spark retardation value DELTA alpha Z1 is increased to a certain retardation correction value or, in the absence of pinking during the observation time, it is reduced to a given advance correction value. The spark timing can thus be adapted rapidly in dynamic processes to achieve optimal operation and a low tendency to pinking.

Selbsttaetige zuendzeitpunkt-anpassung bei dynamik-vorgaengen fuer eine fremdgezuendete brennkraftmaschine

The invention discloses automatic adaptation of spark timing in dynamic processes for a spark-ignition internal combution engine whereby, in a dynamic process, dynamic spark timing retardation values ΔαZ1 are stored in an engine speed characteristic curve and added to a predetermined spark timing value αV in order to retard the spark timing. After a waiting time tW, the spark timing is advanced again to the predetermined value αV. The stored dynamic spark retardation values ΔαZ1 can be varied in a kind of learning process. If a combustion with pinking occurs during an observation time tB, a dynamic spark retardation value ΔαZ1 is increased to a certain retardation correction value or, in the absence of pinking during the observation time, it is reduced to a given advance correction value. The spark timing can thus be adapted rapidly in dynamic processes to achieve optimal operation and a low tendency to pinking.

Gibtner Siegfried Dipl Ing

Papers

Controlled IC exhaust gas buffer and recycle system - improving cold start=up efficiency of catalytic converters using an engine management device

Pressure measurer for IC engine combustion chamber - has measurement chamber in gap between cylinder head and block for measurement free of influence from vibrating parts

Selbsttaetige zuendzeitpunkt-anpassung bei dynamik-vorgaengen fuer eine fremdgezuendete brennkraftmaschine

Automatic adaptation of spark timing in dynamic processes for a spark-ignition internal combustion engine