A method is provided for operating a cooling system of an internal combustion engine, which cooling system has a controllable rotary slide valve with at least one switched inlet or outlet. The movement of the rotary slide valve into a plurality of switching positions, which each correspond with a cooling system state, is monitored. In accordance with an improper functional state of the rotary slide valve and a current switching position of the rotary slide valve, an operating state of the internal combustion engine is changed to an emergency operation state. A protection system in the cooling system carries out the method and includes a thermal management system, which receives and processes coolant temperatures, and a control unit of a controllable rotary slide valve having a position detector, which can detect a current switching position of the switchable rotary slide valve, wherein the thermal management system is connected to the control unit of the rotary slide valve.

The invention relates to a method for operating a cooling system of an internal combustion engine, and to a protection system in a cooling system.
The use of a controllable rotary slide valve with switched inlets permits considerably more flexible and faster regulation of the cooling system in relation to the use of conventional wax actuators.
It is sought, in a cooling system of an internal combustion engine, to realize the most dynamic possible control of the cooling system states, and in particular to be able to set the target temperature in the cooling system as accurately as possible, in order to reduce the emissions of the internal combustion engine. The potential that lies in the switching dynamics should in this case be fully exploited without reducing the functional reliability of the internal combustion engine.
It is an object of the invention to optimize the operation of a cooling system of an internal combustion engine.
This is achieved by way of a method for operating a cooling system of an internal combustion engine, in which a controllable rotary slide valve having at least one switched inlet or outlet is provided. The movement of the rotary slide valve into multiple switching positions which correspond to, in each case, one cooling system state is monitored. In a manner dependent on an improper functional state of the rotary slide valve and a present switching position of the rotary slide valve, an operating state of the internal combustion engine is changed to an emergency operation state.
Owing to the greater possible dynamics, the possibility of a prompt reaction in the event of faults during operation of the rotary slide valve is advantageous.
The monitoring of the rotary slide valve with regard to improper functional states permits a rapid and targeted change of the operating state of the internal combustion engine in order to protect the latter. Furthermore, such monitoring permits a differentiated reaction, such that the emergency operation state only has to be implemented in actually critical situations.
The emergency operation state permits only restricted functioning of the internal combustion engine, and includes for example a limitation of a rotational speed and/or a torque of the internal combustion engine to a predetermined maximum emergency operation value. The limitation of rotational speed and/or torque to the maximum emergency operation value may be performed entirely electronically.
Depending on the detected fault of the rotary slide valve and the present cooling system state, the emergency operation state may be implemented only temporarily or else may be implemented permanently until the fault is eliminated.
It is normally the case that various monitoring and control systems are provided in the vehicle, which are partially separate and partially integrated. For example, components such as the rotary slide valve are in each case connected to an actuation unit, which outputs control commands and which preferably controls the execution thereof. The activation unit diagnoses any faults of the respective component and communicates these to superordinate systems.
The superordinate systems include for example a thermal management system, the correspondingly programmed electronics of which define the cooling system states of the cooling system in accordance with the prevailing requirements by way of suitable specification of the position of the rotary slide valve. The thermal management system advantageously receives feedback regarding actual states of, for example, coolant temperature sensors in individual coolant branches, the present position of the rotary slide valve, and messages regarding any improper states of the rotary slide valve. The thermal management system advantageously has access to control electronics of the internal combustion engine in order to be able to in particular reversibly restrict the rotational speed and/or the torque.
Furthermore, a separate emergency operation management system is preferably provided, which is responsible for triggering a reduction of the torque and/or the rotational speed, as a protective function in certain situations, by accessing the control electronics of the internal combustion engine. The emergency operation management system preferably communicates with the thermal management system and at least with the actuation unit of the rotary slide valve. The emergency operation management system generally effects a permanent and restrictive limitation of the operation of the internal combustion engine in order to reliably prevent damage.
A further superordinate system is for example a general monitoring system of the vehicle which, inter alia, monitors temperature sensors in the cooling system with regard to an exceedance of a setpoint temperature. The general monitoring system preferably communicates with the thermal management system.
The handling of the entire process, from the detection of an improper functional state, via the recording of the fault in a fault memory, the signaling of the fault and the appropriate reaction, to a possible re-enablement of the operating states of the internal combustion engine, may be performed by the thermal management system itself.
In certain cases, it is however expedient to follow a more restrictive approach and to transfer the handling of the fault to the emergency operation management system, which for example keeps the operating state of the internal combustion engine permanently in the emergency operation state until the fault memory is restored in a workshop, and the rotary slide valve is repaired or exchanged.
It is possible, for example upon the next vehicle restart, to check whether the rotary slide valve is again functioning properly. If so, the emergency operation state can be ended again, both by way of the thermal management system and by way of the emergency operation management system.
Depending on the design of the rotary slide valve, it is possible for multiple subcircuits of the cooling system to be simultaneously entirely or partially opened or closed.
Here, it is advantageously the case that, in a proper functional state, the controllable rotary slide valve provides feedback regarding the present switching position, even with regard to partially opened or partially closed inlets or outlets. The respective cooling system state can be identified from the present switching position of the rotary slide valve.
The improper functional state of the rotary slide valve may be defined for example by a movement stiffness of the rotary slide valve, a jamming of the rotary slide valve, a failure of an actuation unit of the rotary slide valve, or a failure of a position detector of the rotary slide valve.
The type of improper functional state, and the cooling system state defined by the present switching position of the rotary slide valve, are crucial for the reaction that is implemented.
One possible critical present switching position of the rotary slide valve corresponds, for example, to a state of the cooling system in which the vehicle cooler (radiator) is at least substantially not traversed by flow. In this case, at most a part of the maximum cooling power is available, and in the case of a high-power demand, that is to say in the case of high-torque and/or high rotational speed of the internal combustion engine, it would be possible for the coolant temperature in the internal combustion engine to rise to an excessively high value. In this case, the internal combustion engine is advantageously placed into the emergency operation state in order to prevent an excessive temperature increase. The initiation of the emergency operation state may possibly be made dependent on further parameters.
A present switching position of the rotary slide valve which corresponds to a state of the cooling system in which a flow through coolant lines in the internal combustion engine is at least partially throttled is to be regarded as being particularly critical. In this switching state, it is normally also the case that the vehicle cooler is not traversed by flow, such that the cooling power of the internal combustion engine is restricted almost or entirely to the minimum cooling power. Intense increases and power of the internal combustion engine could, in this state, lead to overheating. In this case, a rapid and highly restrictive switch to the emergency operation state is recommended.
It is preferably the case that a coolant temperature is detected, and that the operating state of the internal combustion engine is changed to the emergency operation state only above a threshold value temperature.
It is expedient for the coolant temperature to be detected in the region of a cylinder head of the internal combustion engine and/or for a coolant temperature in a coolant line immediately downstream of the internal combustion engine to be detected, that is to say at locations at which the maximum coolant temperature prevails.
If the coolant temperature still lies below the threshold value temperature, the thermal management system may decide that a restriction of the operating state of the internal combustion engine will not yet be performed.
In the above-described particularly critical cooling system states in which the cooler and possibly also the internal combustion engine are not traversed, or are only partially traversed, by a flow of coolant, it is however preferable for the emergency operation state to be immediately initiated regardless of the coolant temperature. This may also arise in the case of improper functional states, that is to say faults of the rotary slide valve which are highly probably permanent and which cannot be eliminated during ongoing driving operation or by way of a restart of the vehicle, for example in the event of the failure of a position detector or of control electronics. The initiation of the emergency operation state may, in such situations, be realized directly by way of the emergency operation manager which receives the respective fault message from the actuation unit of the rotary slide valve, in order to realize the most prompt possible reduction of the heat generation by the internal combustion engine.
In the case of an unthrottled or only partially throttled coolant flow through the vehicle cooler, the emergency operation state can be withdrawn again if the temperature falls below the threshold value temperature. In this case, it is in principle the case that adequate cooling power is available even for relatively high engine speeds and torques of the internal combustion engine. In this case, it may suffice for the coolant temperature to be monitored and for the operation of the internal combustion engine to be restricted only if the coolant temperature exceeds the predefined threshold value. This may be the case for example in the event of brief instances of demand for high power.
An initiation of the emergency operation state may be at least initially permitted if, in the present cooling system state, at least a minimum flow through the vehicle cooler is realized, even if the rotary slide valve is in an improper state, as long as the coolant temperature lies below the threshold value temperature. In the case of the vehicle cooler being partially or fully open, the cooling action is normally adequate for all operating states of the internal combustion engine, that is to say all rotational speed ranges, such that an intervention is necessary only if the coolant temperature rises to too great an extent.
In the case of the vehicle cooler being fully open, and thus in the case of a maximum coolant throughflow, it is possible here to wait for a possible fault message from the general monitoring system of the vehicle, and to implement the emergency operation state only when the general monitoring system responds.
In the case of a partial flow through the vehicle cooler, that is to say in cooling system states with a throttled coolant flow, however, the temperature monitoring is preferably performed by the thermal management system in order to shorten the reaction time before the start of the emergency operation state.
In the case of an improper functional state of the rotary slide valve which is defined by a failure of the position detector of the rotary slide valve, the rotary slide valve may be moved into a predetermined switching position in which the coolant lines in the internal combustion engine are traversed by a flow of coolant. Even if it is no longer possible to obtain reliable feedback regarding the present position of the rotary slide valve, it is possible in many cases for the rotary slide valve to be moved further into a known switching position in which, advantageously, an at least partial flow through the vehicle cooler and/or through the internal combustion engine is realized.
This may be realized for example by way of a movement of the rotary slide valve as far as an end stop. The arrival at the stop may be identified by way of an increased power consumption of the control motor that moves the rotary slide valve.
It is also possible for the rotary slide valve to be moved for a certain time period based on the assumption of the last known switching position, and then, if necessary, for the switching to be at least approximately determined through monitoring of the present coolant temperature.
Alternatively, the last known switching position may be assumed as a present switching position, and the rotary slide valve may be completely deactivated, that is to say locked. The setting of the operating state of the internal combustion engine is in this case performed in accordance with the last known switching position, and possibly the presently measured coolant temperatures. In this case, the emergency operation state is preferably initiated.
The improper functional state of the rotary slide valve referred to as "movement stiffness" is detected if the movement to a second predetermined position from a first predetermined switching position exceeds a setpoint time. As a reaction, a shaking-free step is preferably performed, in which the rotary slide valve is moved quickly between different switching positions multiple times in order to overcome the blockage. The shaking-free step may basically always be performed. Since it however takes a relatively long time, for example up to 20 seconds, it is preferable, in the presence of cooling system states with a throttled coolant flow through the internal combustion engine and possibly through the vehicle cooler and/or with an excessively high coolant temperature, for the emergency operation state to be initiated, that is to say for the rotational speed and/or torque of the internal combustion engine to be reduced, in order to be able to ensure adequate cooling power.
If the shaking-free step is successful, the operating state of the internal combustion engine can be re-enabled by the thermal management system. However, if the shaking-free step is not successful, the thermal management system preferably registers the fault state "jamming", and makes a decision regarding an enablement of the operating state or an initiation of the emergency operation state on the basis of the present switching position of the rotary slide valve and possibly the present coolant temperature.
In the improper functional states of the rotary slide valve and in the case of the emergency operation state of the internal combustion engine being implemented, a fault message is advantageously stored in a fault memory, and/or a fault display is triggered. The storage may be performed in a fault memory of the thermal management system, of the emergency operation management system and/or of the general monitoring system, where it can be read out by technical personnel during a workshop visit. Furthermore, it is possible for warning lamps and/or warning indicators on the dashboard to be activated in order to inform the driver. It is possible for different warning lamps and/or warning indicators to be provided for the emergency operation management system and for the thermal management system.
The method just described may be carried out for example by way of a protection system in a cooling system of an internal combustion engine, wherein the protection system includes a thermal management system, which receives and processes coolant temperatures, and an actuation unit of a switchable rotary slide valve with a position detector which can detect a present switching position of the switchable rotary slide valve, wherein the thermal management system is connected to the actuation unit of the rotary slide valve.
It is preferably the case that, in addition to the thermal management system, an emergency operation management system separate therefrom is provided, which communicates with the thermal management system. The emergency operation management system is preferably connected directly to the actuation unit of the rotary slide valve, and designed such that it can of its own accord, and independently of the thermal management system, trigger an initiation of the emergency operation state.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

Method for operating a cooling system of an internal combustion engine and protection system in a cooling system

Bayerische Motoren Werke Aktiengesellschaft


In a double-effect absorption chiller wherein the vapor of a refrigerant produced by a high temperature generator is supplied to a low temperature generator 12 for condensation, and the refrigerant liquified by condensation is supplied to a condenser 11, a pipe 7 for supplying the refrigerant liquified in the low temperature generator 12 to the condenser 11 therethrough is provided with an orifice 71 and a control valve 81 as pressure adjusting means. A control circuit 9 is connected to the control valve 81 to hold the valve 81 fully open during the period form the start-up of the chiller until the load is stabilized and thereafter gradually decrease the opening degree of the valve 81. Alternatively, a control valve 118 is mounted on the pipe 7 for controlling the pressure of the refrigerant so that the concentration of the absorbent (intermediate solution) in the high temperature generator because equal to the average of the concentration of the absorbent (strong solution) in the low temperature generator 12 and the concentration of the absorbent (weak solution) in an absorber.

FIG. 12 shows a double-effect absorption chiller which comprises an upper shell 1 comprising a condenser 11 and low temperature generator 12, a lower shell 2 comprising an evaporator 21 and absorber 22, a high temperature generator 3 incorporating a burner 31, a high temperature heat exchanger 4, a low temperature heat exchanger 5, etc. These components are interconnected by piping to recycle an absorbent through the high temperature generator 3, low temperature generator 12 and absorber 22 by an absorbent pump 6 and realize refrigeration cycles.
With the chiller of the type described, a pipe 7 for supplying the refrigerant liquefied by the low temperature generator 12 to the condenser 11 therethrough is provided with an orifice 70 as shown in FIG. 13 to reduce the pressure of the refrigerant liquefied by the generator 12 before the refrigerant is supplied to the condenser 11. Thus, the generator 12 is maintained at a low internal pressure so that the vapor of refrigerant produced in the generator 12 is liquefied on condensation in the condenser 11.
On the other hand, the high temperature generator 3 produces vapor of refrigerant, which is condensed in a heat transfer tube within the low temperature generator 12 to liquefy while giving the heat of condensation to the absorber. The liquefied refrigerant is supplied to the condenser 11 via the orifice 70 and then returned to the evaporator 21 along with the portion of refrigerant which is liquefied in the condenser 11.
As shown in FIG. 12, a gas valve 32 is mounted on a pipe for supplying a fuel gas to the burner 31 of the high temperature generator 3. The opening degree of the gas valve 32 is controlled to adjust the rate of supply of the fuel gas in order to maintain the temperature cold water outlet temperature Tc_out) of cold water flowing out of the evaporator 21 at a target value.
With the double-effect absorption chiller, it is ideal that the heat input to the high temperature generator 3 cause the generator 3 to produce an amount of vapor corresponding to the quantity of heat input for the amount of vapor to produce vapor having the same quantity of heat in the low temperature generator 12. A maximum efficiency is achieved at this time. To obtain a state as close as to the ideal, it is necessary to optimize the diameter of the orifice 70 to effect a suitable pressure reduction. The optimum pressure reduction varies with the magnitude of the refrigeration load.
Since there is an approximate proportional relationship between the amount of vapor released from the absorbent and the absorbent concentration difference between the inlet and the outlet of the low temperature generator 12 and the high temperature generator 3, an efficiency approximate to a maximum is obtained when the concentration difference between the absorbent (strong solution) in the low temperature generator 12 and the absorbent (intermediate solution) in the high temperature generator 3 is equal to the concentration difference between the absorbent (weak solution) in the absorber 22 and the absorbent (intermediate solution) in the high temperature generator 3.
However, since the conventional double-effect absorption chiller uses a fixed orifice of definite diameter as the orifice 70, the pressure reduction differs from the optimum value with variations in the refrigeration load.
Further when the absorption chiller is started up, the flow rate of refrigerant from the low temperature generator 12 becomes greater than in the state of stabilized load, so that the orifice 70 used has a greater diameter than is optimum in view of the increase in the flow rate. The conventional chiller of the type described therefore has the problem that while the chiller is in operation with a stabilized refrigeration load after the start-up, the pressure reduction becomes insufficient to result in a lower efficiency. The chiller has another problem that when the refrigeration load decreases, impairment of the efficiency becomes pronounced owing to the escape of vapor.
When remaining unchanged in con cent ration, the absorbent evaporates more easily at a lower temperature because of a drop in boiling point. Accordingly, it is possible to adjust the amount of evaporation by controlling the pressure. However, the pipe 7 for supplying the refrigerant liquefied in the low temperature generator 12 to the condenser 11 is merely provided with the orifice 70 of definite diameter, so that the conventional double-effect absorption chiller is not adapted for the active control of pressure. As a result, even if the high temperature generator 3 and the low temperature generator 12 are rated at a ratio of 1:1 in the amount of evaporation when designed, this balance of 1:1 is upset due to variations in the refrigeration load, leading to a lower efficiency.
Further with the chiller of the type described, the absorbent (intermediate solution) in the high temperature generator 3 is supplied to the low temperature generator 12 by virtue of the pressure difference between these generators 3 and 12, whereby the concentration of the absorbent (strong solution) collected in the low temperature generator 12 is determined. Thus, the concentration of the strong solution is not controlled positively. Nevertheless, the lower the concentration of the strong solution, the greater the flow rate of the recycling absorbent is, entailing an increased energy consumption for the rise of sensible heat of the absorbent, hence the problem of impaired efficiency.
An object of the present invention is to provide a double-effect absorption chiller which achieves a higher efficiency than conventionally regardless of the operating conditions such as refrigeration load.
Another object of the invention is to provide an absorption chiller which is adapted to pass the refrigerant to the condenser without stagnation when the chiller is started up or in the event of a sudden increase in the load and which is capable of giving a suitable reduced pressure to the refrigerant during steady-state operation so as to achieve a higher operating efficiency than in the prior art.
Another object of the invention is to positively control the concentration of the strong solution to achieve an improvement in operation efficiency over the prior art.


The invention provides a device for fine adjustment of a prosthetic valve device and a method of adjusting the position of a prosthetic valve after implantation. The adjustment mechanism includes complementary structures on a valve member and device frame that cooperate to provide relative axial and/or angular motion between the valve member and device frame (and thus the native vessel). The adjustment mechanism of the invention may also include a means for selectively maintaining the relative position of the valve member and device frame. The device and method are particularly applicable for use with a modular prosthetic valve device that is assembled in the body lumen.

The human body contains a wide variety of natural valves, such as, for example, heart valves, esophageal and stomach valves, intestinal valves, and valves within the lymphatic system. Natural valves may degenerate for a variety of reasons, such as disease, age, and the like. A malfunctioning valve fails to maintain the bodily fluid flow in a single direction with minimal pressure loss. An example of a malfunctioning valve is a heart valve that may be either stenotic, i.e., the leaflets of the valve do not open fully, or regurgitant, i.e., the leaflets of the valve do not close properly. It is desirable to restore valve function to regain the proper functioning of the organ with which the valve is associated. For example, proper valve function in the heart ensures that blood flow is maintained in a single direction through a valve with minimal pressure loss, so that blood circulation and pressure can be maintained. Similarly, proper esophageal valve function ensures that acidic gastric secretions do not irritate or permanently damage the esophageal lining.
Several percutaneous prosthetic valve systems have been described. One example described in Andersen, et. al. (U.S. Pat. No. 5,411,552) comprises an expandable stent and a collapsible valve which is mounted onto the stent prior to deployment. Spenser, et. al. (U.S. Pat. No. 6,893,460) describe another prosthetic valve device comprising a valve structure made of biological or synthetic material and a supporting structure, such as a stent. The Spenser prosthetic valve is a crimpable leafed-valve assembly consisting of a conduit having an inlet and an outlet, made of pliant material arranged to present collapsible walls at the outlet. The valve assembly is affixed to the support stent prior to deployment. The complete valve device is deployed at a target location within the body duct using a deploying means, such as a balloon catheter or a similar device. Percutaneous implantation of medical devices, particularly prosthetic valves, is a preferred procedure because it allows implantation without the need for opening a large portion of the chest.
Accurate placement of current percutaneous valve devices relative to the existing native anatomy is often problematic, particularly in the case of aortic valve replacements. Consequences of poor valve placement in the case of an aortic valve include functional and/or physical occlusion of the orifice of the coronary artery distal to the aortic valve, and/or increased pressure on and disruption of the electrical conduction apparatus of the heart. Specifically, a prosthetic valve that is placed too distally (i.e., toward the aorta) can occlude or impede flow into the orifices of the coronary arteries. For example, depending on the position of the coronary ostia, either the skirt of the prosthetic valve or large native valve leaflets pressed down against the aorta wall may physically or functionally obstruct the orifices and impede coronary arterial flow. See, e.g., Piazza, N., et al., "Anatomy of the Aortic Valvar Complex and Its Implications for Transcatheter Implantation of the Aortic Valve," CIRCULATION CARDIOVASCULAR INTERVENTIONS, 1:74-81 (2008); Webb, J G, et al., "Percutaneous aortic valve implantation retrograde from the femoral artery," CIRCULATION, 113:842-850 (2006). This obstruction may be either physical or it may be functional, i.e., the orifices of the coronary arteries are physically patent, but due to alterations in flow patterns produced by the prosthetic valve, flow into the coronary arteries is partially impeded. A prosthetic valve that is placed too proximally (i.e., toward the ventricular outflow tracts of the left ventricle) can interfere with the anterior leaflet of the Mitral valve, the atrioventricular node or the bundle of His (conduction tissues). Approximately thirty percent of patients receiving prosthetic valves percutaneously require pacemakers, because the valve is placed with the ventricular end too close to or on top of the left bundle branch, putting pressure on the electrical conduction apparatus. See, e.g., Piazza, N., et al., "Early and persistent intraventricular conduction abnormalities and requirements for pacemaking following percutaneous replacement of the aortic valve," JACC CARDIOVASCULAR INTERVENTIONS, 1:310-316 (2008); Piazza, N., et al., "Anatomy of the Aortic Valvar Complex and Its Implications for Transcatheter Implantation of the Aortic Valve," CIRCULATION CARDIOVASCULAR INTERVENTIONS, 1:74-81 (2008).
Persons of skill in the art recognize that one limitation on percutaneous prosthetic aortic valve replacement methods using currently available pre-assembled valve devices is a less than desirable level of precision for positioning the valve. See Ussia, G. P., et al., The "Valve-in-Valve Technique: Transcatheter Treatment of Aortic Bioprosthesis Malposition," CATHETERIZATION CARDIOVASCULAR INTERVENTIONS, 73:713-716 (2009); Ghanbari, H., et al., "Percutaneous Heart Valve Replacement: An Update," TRENDS CARDIOVASCULAR MEDICINE, 18:117-125, (2008); Lutter, G., et al., "Percutaneous Valve Replacement: Current State and Future Prospects," ANNALS THORACIC SURGERY, 78:2199-2206 (2004).
Repositioning methods have been proposed. Such methods involve a repositioning of the entire valve device rather than adjustment from the previous position. One method of repositioning a percutaneous prosthetic valve involves compressing or relaxing the stent that serves as the frame for the valve. See Zegdi, R. et al., "A Repositionable Valve Stent for Endovascular Treatment of Deteriorated Bioprostheses," J. AMERICAN COLLEGE CARDIOLOGY, 48(7):1365-1368 (2006). Such a method provides little if any fine control over the axial position or angular position of the valve, and risks significant shifting of the entire device and/or damage to the tissue. Another method of repositioning a percutaneous prosthetic valve involves preventing the stent from fully expanding until it is in position, or unexpanding the stent slightly in order to reposition it. Buellesfeld, et al., "Percutaneous Implantation of the First Repositionable Aortic Valve Prosthesis in a Patient with Severe Aortic Stenosis," CATHETERIZATION CARDIOVASCULAR INTERVENTIONS, 71:579-584 (2008); US Published Application No. 2005/0137688A1 to Salahieh et al. Such a method provides little if any fine control over the axial position or angular position of the valve, and repeated expansion and compression of the stent at or near the site of implantation risks damage to the tissue.
Therefore, there is a need in the art for an apparatus and method for making fine adjustments to a valve's position after implantation—i.e., to move the valve in small increments until the proper position is achieved. This adjustment method provides an iterative feedback process where each adjustment is an incremental improvement over the last position. A need also exists for a method of delivering a prosthetic valve with increased safety, e.g., with minimal damage to the vessel wall and with good control of the adjustment process. A device that can be placed in the vessel without incurring further damage to the wall of the body lumen during delivery and/or during adjustment of the valve position—e.g., adjusting the valve, not the frame—is highly desirable.

Method and apparatus for fine adjustment of a percutaneous valve structure


A method of manufacturing a semiconductor device that eliminates the n+ contact implant by using double diffused implants under the core cell contacts by forming core, n-channel and p-channel transistors in a semiconductor substrate, simultaneously forming source and drain DDI implants for the core transistors, forming source and drain Mdd implants for the core transistors, forming source and drain Pldd implants for the p-channel transistors, forming source and drain Nldd implants for the n-channel transistors, forming sidewall spacers on the core, n-channel and p-channel transistors, forming N+ implants for the n-channel transistors, forming P+ implants for the p-channel transistors and forming P+ contact implants for the p-channel transistors.

1. Field of the Invention
This invention relates generally to the manufacture of high density, high performance semiconductor devices. More specifically, this invention relates to the manufacture of high density, high performance semiconductor devices utilizing a reduced number of steps during the manufacturing process.
2. Discussion of the Related Art
In order to remain competitive, a semiconductor manufacture must continuously increase the performance of the semiconductor integrated circuits being manufactured and at the same time, reduce the cost of the semiconductor integrated circuits. Part of the increase in performance and the reduction in cost of the semiconductor integrated circuits is accomplished by shrinking the device dimensions and by increasing the number of devices per unit area on an integrated circuit chip. Another part of reducing the cost of a semiconductor chip is to increase the throughput of the fabrication facility (the xe2x80x9cfabxe2x80x9d).
A single semiconductor chip requires numerous process steps such as oxidation, etching, metallization and wet chemical cleaning. Some of these process steps involve placing the wafer on which the semiconductor chips are being manufactured into different tools during the manufacturing process. As can be appreciated, a reduction in the number of process steps in which the semiconductor wafers must be moved from one tool to another can be a major increase in the throughput of the tab as well as a major decrease in the cost of manufacturing the chips on the semiconductor wafer.
Therefore, what is needed are methods of reducing the number of processing steps necessary to manufacture semiconductor wafers on which semiconductor integrated chips are manufactured.
According to the present invention, the foregoing and other objects and advantages are obtained by a method of manufacturing a semiconductor memory device that reduces the number of manufacturing steps required to manufacture the device.
In accordance with an aspect of the invention, the method includes the following sequence of steps; core, n-channel and p-channel transistors are formed in a semiconductor substrate, source and drain DDI (double diffused implant) implants are simultaneously formed for the core transistors, source and drain Mdd (modified drain diffusion) implants are formed for the core transistors, source and drain Pldd (P lightly doped drain) implants for the p-channel transistors, source and drain Nldd (N lightly doped drain) implants are formed for the n-channel transistors, sidewall spacers are formed on the core, p-channel and n-channel transistors, N+ implants are formed for the n-channel transistors and P+ implants are formed for the p-channel transistors.
In accordance with another aspect of the invention, P+ contact implants are formed for the p-channel transistors.
The described method thus provides a method for reducing the number of manufacturing steps required to manufacture a semiconductor memory device.
The present invention is better understood upon consideration of the detailed description below, in conjunction with the accompanying drawings. As will become readily apparent to those skilled in the art from the following description, there is shown and described an embodiment of this invention simply by way of illustration of the best mode to carry out the invention. As will be realized, the invention is capable of other embodiments and its several details are capable of modifications in various obvious aspects, all without departing from the scope of the invention. Accordingly, the drawings and detailed description will be regarded as illustrative in nature and not as restrictive.

Elimination of n+ contact implant from flash technologies by replacement with standard double-diffused and n+ implants


A sensor having a wide sensing range is capable of being controll by a small scale processor. The sensor comprises: a plurality of planar zigzag coils being provided on substrates, the planar zigzag coils having the same coil pitch and being formed into zigzag shape in a first direction, the planar zigzag coils being capable of relative movement in the first direction, the planar zigzag coils including a first planar zigzag coil, which is a primary coil, and a second planar zigzag coil, which is a secondary coil; a magnetizing unit for magnetizing the first planar zigzag coil; a first detecting unit for detecting induced electromotive force, which is induced in the second planar zigzag coil by the first magnetized planar zigzag coil; and a second detecting unit for detecting displacement length between the first planar zigzag coil and the second planar zigzag coil on the basis of the induced electromotive force in the second planar zigzag coil. Therefore, the sensor is capable of having a wide sensing range in which the first planar zigzag coil induces the second planar zigzag coil.

The present invention relates to a sensor, and more precisely relates to a sensor, which is capable of detecting displacement length on the basis of mutual displacement length of coils.
Many types of sensors have been known. The applicant of the present invention also invented a displacement sensor. The displacement sensor was disclosed in U.S. Pat. No. 5,046,702. The displacement sensor has a coil, a diaphragm and a magnetizable body, which is fixed to the diaphragm and is capable of moving close to and away from the coil. When the magnetizable body moves close to and away from the coil with the movement of the diaphragm, reactance of the coil changes, so that displacement length of the diaphragm can be known by detecting the change of reactance thereof.
However, the conventional sensor has the following disadvantages.
Firstly, while the magnetizable body moves to the coil from outside, the reactance of the coil changes suddenly; on the other hand, while the magnetizable body goes into the coil, the reactance thereof changes gradually. Therefore, a practical sensing range, in which the displacement length of the magnetizable body can be practically detected, is limited to a range until the magnetizable body reached the coil. In other words, the displacement sensor has a small sensing range.
Secondly, a processor, which is capable of processing large amount of data, is required so as to convert the change of the reactance to the displacement length of the diaphragm because the reactance changes curvedly.

Sensor having mutually perpendicular sections using zigzag coils for detecting displacement


The present invention relates to a method for generating and causing display of a communication interface that facilitates the sharing of emotions through the creation of 3D avatars, and more particularly with the creation of such interfaces for displaying 3D avatars for use with mobile devices, cloud based systems and the like.

Increased prevalence of mobile devices has resulted in "social networking" to become an important part in the day-to-day activities of many people's lives. Today, hundreds of millions of people use their virtual identities to communicate and interact with other people over the web, internet and the like via Social networking sites. In addition, these virtual identities are used to play games over the web, internet and the like.
While social networking provides the ability for contact between people any time of day or night, it is often difficult to ascertain exactly how people are feeling by looking at their virtual identity, or through reading text messages alone. An improvement to existing social networking sites would therefore be a means to facilitate the conveyance of moods, feelings, sentiments etc. can be made available via the web, Internet and the like.


A method of controlling display of object data includes calculating distances from a terminal to the positions of multiple items of the object data, determining, by a processor, an area based on the distribution of the calculated distances, and displaying object data associated with a position in the determined area on a screen.

An augmented reality (AR) technique to display object data over part of an image captured with an image capturing device such as a camera is known. For example, based on the position information of a terminal measured using the Global Positioning System (GPS) and on the inclination information of the terminal, object data are displayed over the image captured by the terminal on its screen.
Furthermore, there is a technique to display the position information of surrounding preset object data in a radar map in order to have a user understand at which position around the position information of the terminal the object data are located. The range of the radar display may be set by the user, and the object data are displayed over the image on the screen of the terminal in accordance with the set range.
International Publication Pamphlet No. WO 2012/127605 and Japanese Laid-open Patent Publication No. 2012-38248 may be referred to for related art.

Display control method and information processing apparatus


A light-emitting device and a manufacturing method thereof, and an electronic apparatus are disclosed. The light-emitting device includes: a base substrate, a light-emitting unit, an encapsulation cover plate and a light-guiding structure. The light-emitting unit is on the base substrate; the encapsulation cover plate is opposite to the base substrate and covers the light-emitting unit; and the light-guiding structure is at a light exiting side of the light-emitting unit and includes a plurality of first structures. The light-guiding structure is configured to enable light emitted by the light-emitting unit to be incident into the first structures and enable the light to exit from the encapsulation cover plate.

Organic light-emitting diodes (OLED) have characteristics, such as self-luminescence, high brightness, wide viewing angle, high contrast, low energy consumption, etc., and have attracted much attention and have widely been used in mobile phone screens, computer monitors, full-color televisions, etc. In an OLED encapsulation structure or an OLED display device, light is emitted from a side of an encapsulation cover plate or the side, opposite to the encapsulation cover plate, of a base substrate. The light emitted by an OLED element is in all directions, and passes through the space between the encapsulation cover plate and an OLED substrate before exiting from the encapsulation cover plate or from the base substrate as well as two surfaces of the encapsulation cover or the plate base substrate.

Light-emitting device and manufacturing method thereof, electronic apparatus

Hefei Xinsheng Optoelectronics Technology Co., Ltd.


A write assist driver circuit is provided that assists a memory cell (e.g., volatile memory bit cell) in write operations to keep the voltage at the memory core sufficiently high for correct write operations, even when the supply voltage is lowered. The write assist driver circuit may be configured to provide a memory supply voltage VddM to a bit cell core during a standby mode of operation. In a write mode of operation, the write assist driver circuit may provide a lowered memory supply voltage VddMlower to the bit cell core as well as to at least one of the local write bitline (lwbl) and local write bitline bar (lwblb). Additionally, the write assist driver circuit may also provide a periphery supply voltage VddP to a local write wordline (lwwl), where VddP≧VddM>VddMlower.

1. Field
The present disclosure pertains to memory devices with improved writeability of memory cells at low voltage levels.
2. Background
With increased scalability of semiconductor devices, two goals are to make such semiconductor devices more dense and power efficient. Lowering the operating voltage is sometimes used to achieve power efficiency. In the case of memory devices, the lowered voltage may cause reliability issues when writing to memory cells due to unstable behavior of transistors therein.
FIG. 1 illustrates a conventional memory cell 102 comprising a cell core 114 (first inverter 104, and second inverter 106), a first write transistor 108, a second write transistor 110, and a pair of read access transistors 112. FIG. 2 illustrates a detailed implementation of part of the memory cell 102 of FIG. 1. In one example, the memory cell 102 may be a volatile memory.
The cell core 114 may include a first inverter 104, including a first driver transistor 206 (FIG. 2, pull-down transistor) and a first load transistor 208 (pull-up transistor), and a second inverter 106, including a second driver transistor 202 (pull-down transistor) and a second load transistor 204 (pull-up transistor). In this example, the load transistors 204 and 208 (pull-up transistors) are P-channel metal-oxide-silicon (PMOS) transistors and the driver transistors 202 and 206 (pull-down transistors) are N-channel metal-oxide-silicon (NMOS) transistors. The bit cell 102 may be coupled to a write bitline (WBL) 118, a write bitline bar (WBLB) 120, and a write wordline (WWL) 116 that operate together to store one bit of information in the cell core 114. When the write wordline (WWL) 116 is asserted (i.e., goes to a high state), the states at the write bitline (WBL) 118 and the write bitline bar (WBLB) 120 are stored in the cell core 114. The bit cell 102 may also be coupled to a read bitline (RBL) 122 and a read wordline (RWL) 124 that operate together to read one bit of information from the cell core 114. When both the read bitline (RBL) 122 and read wordline (RWL) 124 are asserted (e.g., goes to a high state), a bit is read through the read access transistors 112. In some exemplary implementations, the wordlines WWL 116 and RWL 124, and the bitlines WBL 118, WBLB 120, and RBL 122 may be shared among a plurality of bit cells such that just one bit cell is selected from the plurality of bit cells by a particular combination of wordline and bitline.
The first inverter 104 has its output coupled to the drain of the second write transistor 110 at Node-B. For instance, as illustrated in FIG. 2, the drain of the first load transistor 208, the source of the first driver transistor 206, and the drain of the second write transistor 110 are coupled at Node-B. The gate of the first driver transistor 206 and the gate of the first load transistor 208 are coupled together to the output (i.e., Node-A) of the second inverter 106.
Similarly, the second inverter 106 has its output coupled to the drain of the first write transistor 108 at Node-A. For instance, as illustrated in FIG. 2, the drain of the second load transistor 204, the source of the second driver transistor 202, and the drain of the first write transistor 108 are coupled at Node-A. The gate of the second driver transistor 202 and gate of the second load transistor 204 are coupled together to the output (i.e., Node-B) of the first inverter 104. Thus, in this conventional manner the first inverter 104 and second inverter 106 are cross-coupled, meaning that the output of each inverter is connected to the input of the other, to form the cell core 114 that stores a single bit of information.
The drain of the first write transistor 108 is connected to the output of the second inverter 106 (i.e., Node-A). Similarly, the complimentary second write transistor 110 is coupled to the output of the first inverter 104 (i.e., Node-B). The gates of the second write transistor 110 and first write transistor 108 are each connected to a write wordline (WWL) 116. Together, the second write transistor 110 and the first write transistor 108 form a write circuit that imposes a state on the memory cell 102 in cooperation with the WWL 116, a write bit-line (WBL) 118 and a complementary write bit-line (WBLB) 120.
If the WBL 118 is set to a value of Vdd (logical 1 or high) while the WBLB 120 is set to a value of Vss (logical 0 or low), then, when the WWL 116 is asserted (set to Vdd, high or logical 1), the output Q (Node-A) of the second inverter 106 will be set to a value of Vdd-Vtn, where Vtn is the threshold voltage of the first write transistor 108, while the output Q-Bar (Node-B) of the first inverter 104 will be set to Vss. This is because the second write transistor 110 (e.g., an NMOS transistor) starts in a saturation region of operation and ultimately operates in a linear region when its drain-source voltage Vds=0. The second load transistor 204 (e.g., PMOS) of the second inverter 106 restores Node-A to full Vdd once Node-B reaches Vss.
Conversely, if WBL 118 is set to Vss (logical 0 or low) and WBLB 120 set to Vdd (logical 1 or high), when the WWL 116 is asserted (set to Vdd, high, or logical 1), the output Q (Node-A) of the second inverter 106 will be set to a value of Vss, while the output Q-Bar (Node-B) of the first inverter 104 will be set to Vdd-Vtn, where Vtn is the threshold voltage of the second write transistor 110. The first load transistor 208 (e.g., PMOS) of the first inverter 104 restores Node-B to full Vdd once Node-A reaches Vss.
In the situation in which Node-A is initially at Vdd (e.g., high or logical 1), WBL 118 is set to Vss (logical 0 or low), and WWL 116 is enabled (e.g., Vdd, high or logical 1), writeability of the memory cell 102 of FIG. 1 involves a fight between the first write (NMOS) transistor 108 and the second load (pull-up PMOS) transistor 204. The first write transistor 108 has to be strong enough to cause Node-A to discharge to Vss while the second load transistor 204 is trying to retain Node-A at Vdd (e.g., high or logical 1).
Similarly, in the situation in which Node-B is initially at Vdd (e.g., high or logical 1), WBLB 120 is set to Vss (logical 0 or low), and WWL 116 is enabled (set to Vdd, high, or logical 1), writeability of the memory cell 106 of FIG. 1 involves a fight between the second write transistor 110 and first load transistor 208. The second write transistor 110 has to be strong enough to cause Node-B to discharge to Vss while the second load transistor 204 is trying to retain Node-B at Vdd (e.g., high or logical 1). Hence, the write transistors 108 and 110 are usually stronger than the load (pull-up) transistors 204 and 208.
FIG. 3 illustrates the conditions of writeability for the memory cell 102 of FIGS. 1 & 2 at a nominal Vdd source voltage. These graphs illustrate the conditions at the bitlines WBL 118 and WBLB 120 and outputs Q (Node-A) and Q-Bar (Node-B) during a write operation when the wordline (WWL) 116 is switched from low (e.g., logical 0 or nominal Vss voltage) to high (e.g., logical 1 or nominal Vdd voltage). When the WBL 118 is set to low (e.g., logical 0 or Vss) while the WBLB 120 is set to high (e.g., logical 1 or Vdd), and then the WWL 116 is asserted (set to high, Vdd, or logical 1), the output Q (Node-A) of the second inverter 106 will be set to a value of Vdd (e.g., logical 1 or high), while the output Q-Bar (Node-B) of the first inverter 104 will be set to Vss (e.g., logical 0 or low).
FIG. 4 illustrates the condition of writeability for the memory cell 102 of FIG. 1 at a low source Vdd voltage (Vddlow). The low source Vdd voltage (Vddlow) may occur, for example, when a device enters a power conservation state in which a lower source voltage is used, when a device uses a lower voltage power source (e.g., a portable or mobile device), and/or when a source voltage from a portable power source (e.g., battery) diminishes (e.g., as the battery drains). For the same write operation illustrated in FIG. 3, but at the lower Vddlow voltage, it can be seen that the outputs Q (Node-A) and Q-Bar (Node-B) may not reach the correct state (i.e., the outputs Q and Q-Bar do not change logical states when the WBL and WBLB change logical states).
Under normal source voltage Vdd, in order to write into the memory cell 102, the write transistors 108 and 110 may be stronger than the load transistors 204 and 208 (pull-up transistors) and/or the write transistors 108 and 110 may be the same strength/size as the driver transistors 202 and 206 (pull-down transistors) of the inverters 104 and 106 in order to write the correct bit.
However, at a low voltage of Vddlow the write transistors 108 and 110 might not be stronger than the load transistors 204 and 208 (pull-up transistors) and/or driver transistors 202 and 206 (pull-down transistors). For instance, at low voltage of Vddlow when a write operation is attempted with WBL=low and WBLB=high, the gate of the first write transistor 108 may be lowered to Vddlow which may just exceed the NMOS threshold voltage Vtn by not more than a few hundred milli-volts (mV).
If a low source voltage Vddlow is used at the gate of the first write transistor 108, the gate-to-source voltage Vgs for the first write transistor 108 may be approximately the threshold voltage Vtn, then the resistance across the first write transistor 108 (which is very weakly turned ON) is very high compared to the resistance across the first load transistor 204. Also, when the low source voltage Vddlow is used (e.g., Vgs˜Vtn), the current through the first write transistor 108 is very low compared with the current through the first write transistor 108 when typical source voltage Vdd is used. Consequently, the first write transistor 108 cannot drive the voltage at Node-A to low (e.g., Vss or logical 0) because the first load transistor 204 (pull-up transistor) is stronger (e.g., less resistive) than the first write transistor 108. As a result, the stronger first load transistor 204 maintains Node-A (Q) at high (e.g., logical 1 or Vdd) as illustrated in FIG. 4.
Similarly, if a low source voltage Vddlow is used at the gate of the second write transistor 110, the second write transistor 110 may not be able to drive the voltage at Node-B (Q-Bar) high (Vdd or logical 1) because the first driver transistor 206 (pull-down transistor) may be stronger than the second write transistor 110. As a result, the stronger first driver transistor 206 maintains Node-B (Q-Bar) at low (logical 0 or Vss) as illustrated in FIG. 4. Thus, such low voltage conditions may inhibit the proper operation of memory cells.
Consequently, a solution is needed that allows memory cells to operate correctly at lowered voltages.

Write driver for write assistance in memory device


A rubber grinding machine and method is provided for ambient temperature grinding of rubber material to form finely ground rubber particles. The rubber grinding machine includes a feed tube, a grinding module, a conveyor, a screening module and a vacuum system. Rubber material is placed in the feed tube which advances the rubber material into the grinding module using a plunger or auger. The grinding module includes a grinding wheel which grinds the rubber material into rubber particles. The grinding wheel is surrounded by a shroud which includes a water-cooled cooling jacket. The water is circulated through the cooling jacket to cool the shroud and its interior. Rubber particles ground by the grinding wheel fall through the bottom of the shroud onto a conveyor which deposits the rubber particles onto the screen module. The screen module includes at least one screen for separating the rubber particles by size. Rubber dust produced by the grinding wheel is processed by a vacuum system and may later be screened.

The present invention relates to a rubber granulating machine and method, and more particularly to a process and apparatus for grinding rubber or similar material. The rubber or similar material is ground into a usable or marketable end product such as rubber powder that may be used in the rubber industry.
The disposal or reuse of previously used rubber products, such as rubber tires, presents many problems. Ecologically, rubber tires degrade very slowly and if disposed of improperly, may lead to hazardous environmental conditions in terms of both potential ground water problems and other ecological effects. Recently, recycling of pre-used rubber products has increased in popularity in order to avoid potential negative environmental impact as well as to provide potentially commercially reusable rubber products.
Several methods for recycling used rubber products exist. Often, rubber products such as rubber tires are rendered into dust or fine particulate rubber which then may be reused in other rubber products. However, one of the difficulties with recycling rubber products such as tires is that such products are extremely durable and consequently difficult to reduce to a re-usable form. In order for any recycling effort to be cost effective, a method must be developed to reduce the extremely durable rubber products to a form of rubber that may be useable in further generating processes. Recycled rubber particles become more commercially valuable with decreasing particle size. The commercial value increases because rubber particles of smaller sizes may be more easily incorporated into a wider variety of new rubber products.
U.S. Pat. No. 4,813,614 issued to Moore et al. entitled, "Method and Apparatus for Treating Waste Products to Recover the Components Thereof" illustrates an early method for recovering rubber particles from pre-used rubber products such as tires. In Moore, used products such as used rubber tires are frozen using liquid nitrogen and are then crushed. The particles are re-frozen and re-crushed in successive stages to yield finer and finer rubber particles. The crushed output is then separated with regard to the size of the crushed particles and crushed particles may then be sold and/or reused based upon their size. In order to lower the temperature of the rubber tires sufficiently so that the rubber tires behave more solidly and less elastically so that the rubber tires may be crushed, Moore relies on a large quantity of liquid nitrogen. Liquid nitrogen is, of course, expensive to use. Thus, although the Moore process may yield fine particulate rubber, it is quite expensive.
U.S. Pat. No. 5,695,131 issued to Wenzel entitled "Shredder Separator" illustrates another device for recycling used rubber products such as rubber tires. The shredder separator of Wenzel includes a number of rotating blades that cut or shred a tire into small pieces. The shredding separator of Wenzel operates at ambient (i.e., generally room temperature) and thus avoids the expensive liquid nitrogen cooling steps of Moore. However, the product output by Wenzel's shredder is undoubtedly inferior to the product output by Moore for use in new rubber products because of the larger output size of the rubber particles. Because the shredder relies on a number of rotating blades rather than successive crushing steps, the recycled rubber particles are far larger than the rubber particles of Moore and consequently less commercially desirable for many applications. While large size particles may be suitable to such applications such as playground flooring and the like, the output of Wenzel is less suitable for reconstitution into new rubber products. By comparison, the fine rubber particles of Moore may be considerably more easily and economically incorporated into new rubber products.
U.S. Pat. No. 5,299,744 to Garmater entitled "Granulating Separating and Classifying Rubber Tire Materials" illustrates a further system for recycling used rubber tires. As with Wenzel, Garmater includes a rotating cutter wheel for reducing large chunks of tire into smaller chunks which may be reusable for some purpose such as ground cover for playgrounds, jogging trails, and the like. As with Wenzel, the rubber particles produced by Garmater are fairly large and maybe suitable for ground cover applications rather than applications such as reconstitution into new rubber products.
Thus, rubber recycling reclamation or granulating machines may be classified into two types. A first type produces fairly large rubber particles and operates at room temperature, often using rotating knives or knives of some sort to produce the particles. The process is fairly inexpensive. However, the large rubber particles produced, while usable for applications such as ground cover, are not generally usable for more commercially desirable applications such as new rubber products. A second type of rubber reclamation is the type shown in Moore in which the machinery operates at extremely lower temperatures and produces fine particles. Because the process operates at low temperatures, the process is fairly expensive. The rubber particles produced, however, may be employed in new rubber products.
Additionally, although the processes of Wenzel and Garmater may produce some small amount of fine particles, for example as a byproduct of the process, such particles are a very small fraction by weight of the output of the process. Only a small fraction of the total rubber material processed using the processes of Wenzel or Garamater may yield fine particle sizes.
Thus, a need exists for an improved method and apparatus for reducing rubber products such as pre-used rubber products, into fine grain particles with a high process efficiency. A need has especially existed for such a method and apparatus able to operate with lower cost.
It is therefore an object of the present invention to minimize the expense of producing commercially reusable rubber particles by providing a cost-effective, generally ambient temperature process that eliminates costly liquid nitrogen freezing.

Method and apparatus for grinding rubber


A method for handling an Implantable Medical Device, IMD, transmission from an IMD provider such that the transmission comprises one or more alerts and/or IMB data attributes indicative for a status of the IMD or the patient. The alert comprises a provider specific alert priority. The method comprises the following steps: retrieving the IMD transmission from the IMD provider; and assigning to the one or more alerts a generic alert severity based on a predetermined mapping between the provider specific alert priority and the generic alert severity; and/or calculating an IMD data severity based on the IMD data attributes; and calculating a transmission severity based on the generic alert severity assigned to the one or more alerts and/or the IMD data severity.

Most IMDs available on the market today can communicate wirelessly with an external communication device. An IMD will monitor both the condition of the patient and the condition of the IMD itself. When an abnormal condition is detected, the IMD issues an alert and communicates it as part of a transmission to the external communication device. Transmissions may also be sent if there is no abnormal condition. In such a case the transmission may comprise some data attributes indicative for the status of the device or the status of the patient. Transmissions may further be initiated by the IMD itself or by the patient. Typically, to save power, the external communication device is located within close range of the patient in order to limit the power consumption of the wireless communication. The external communication device functions as router and forwards the alert to a central IMD management system.
Typically, such an IMD management system is managed by the vendor or provider of the IMD. Medical or technical staff can then log onto this system to view and handle transmissions generated by the IMDs.
US2010/0123587 discloses such an alert management system that can be used by a provider of IMDs. Incoming alerts are managed by processing values of parameters related to the alert such that appropriate actions can be taken. This way a relatively small number of parameters can be defined to manage a relatively large number of different alerts.
US2006/0017575 discloses such an alert management system that can be accessed by a care giver through a web interface. The care giver may then change different settings for the alerts and even define certain clinical or device alerts.
US2012/0108917 discloses such an alert management system wherein the IMD-generated alerts can be customized in many ways so as to suit the health condition and personal circumstances of each individual patient. The alerts can also be customized to provide an appropriate alert for each individual patient corresponding to a patient-initiated emergency notification transmission from the patient's adherent device.
A problem with the existing solutions is that all IMD management systems are vendor or provider specific. Medical or technical staff has to access all IMD management systems separately for each vendor or provider and thus lacks a unified overview.

Transmission handling of medical devices


A plastic housing has a front shell with inwardly protruding bristles of an exterior wire brush, and a rear shell which retractably receives the outwardly protruding bristles of an interior wire brush. The interior brush is mounted to a shaft which engages the housing, and which is driven by a motor, such as by a power drill. A ring-like deburring element is mounted to the shell between the front shell and the rear shell, and has an inwardly and frontwardly protruding generally frustoconical first wall forming a deburring element which defines a central opening through which the interior brush may be projected and retracted. The first wall may be planar segments, or may have a circular cross section. The deburring element serves to position a pipe for burnishing by the exterior brush, and also deburrs the end of the inserted pipe.

The present invention relates to apparatus for treating the cut ends of pipes and fittings.
The exposed portions of copper and brass pipes and fittings are subject to corrosion and contamination which can interfere with the action of surface tension which draws solder or braze alloy into contact when the pipes or fittings are soldered or brazed together. Thus it is required to clean the pipe surfaces which are to be joined. Moreover, in some applications it is required to remove the projecting burrs of copper or brass before joining the pipes. Although many tools are available to perform the burnishing of a pipe interior or exterior, or to deburr a pipe, convenience and ready availability of all necessary tools can speed along the process of preparing multiple pipe surfaces. What is needed is an economical tool which provides convenient burnishing and deburring of pipes and fittings.


A process for producing agglomerates with a core/shell structure, in which i) initial agglomerates containing a first particulate solid are prepared; ii) a second particulate solid is agglomerated in the presence of the initial agglomerates with the addition of a binder liquid to give second stage agglomerates and, where appropriate, iii) an nth (nxe2x89xa73) solid is agglomerated in the presence of the (nxe2x88x921)th stage agglomerates with the addition of a binder liquid to give nth stage agglomerates.

This application is a 371 of PCT/EP99/09462 filed Dec. 3, 1999.
The present invention relates to a process for producing agglomerates with a core/shell structure and to the agglomerates obtainable thereby.
Agglomeration is to be understood here to be a process in which fine-pile substances are clumped together by wetting with a liquid with simultaneous mechanical agitation to give conglomerates, i.e. pellets or granules. The resulting agglomerates are assemblages of particles in which the original particles are not completely fused together, it being possible, for example by microscopic examination, still to recognize the outlines of some of the individual particles. An agglomerated material has numerous advantages over the fine-particle starting material. Thus, certain properties such as strength, size, shape and porosity can be adjusted in a defined manner, which is noticeably advantageous on storage, transport and metering. Any homogeneities are prevented, the bulk properties are improved and the formation of dust during packaging and transferring is reduced. This increase in quality makes the additional agglomeration processing step justifiable in the manufacture of numerous products such as drugs.
In what is called agitative agglomeration there is automatic attachment of the particles together on wetting with liquid on the reaction of interfacial forces while the material is agitated mechanically.
A special type of agitative agglomeration is rewetting agglomeration. The basis for this is a 3-phase mixture which consists of a fine material to be agglomerated and of a suspending liquid and a binder liquid which must not be miscible with one another. The binder liquid must have the property of wetting the suspended material better than does the suspending liquid. The fine material to be agglomerated is present in suspended form in the suspending liquid. The binder liquid is then introduced and interacts with the fine particles and leads to particle size enlargement. The granules which are formed are removed from the reusable suspending liquid, for example using a filtration apparatus.
Many drugs can be administered in solid form as agglomerates. These dissolve in the body over a certain period. The rate of dissolution is determined by the area of the drug available for attack by body fluid, i.e. the surface area of the drug. If the surface area is reduced by the dissolution process, a smaller amount of active ingredient is released per unit time. However, for most applications a constant rate of release of active ingredient is desired. One aspect of the present invention is therefore based on the object of indicating a process for producing agglomerates which show essentially uniform release of active ingredient throughout the dissolution period.
It is often desirable to produce solid drug forms with more than one active ingredient, with the active ingredients being released at different times.
Another aspect of the invention is therefore based on the object of indicating a process for producing agglomerates which contain different active ingredients which are released successively.
DE-A 44 00 295 describes a spherical granulum which is prepared by introducing lactose particles into a granulating and coating apparatus equipped with a horizontal rotating disk having a flat contacting surface towards the granula, and spraying a lactose solution during rotation of the rotating disk. The granulum is useful as carrier for drugs and foodstuff.
We have found that the above objects are achieved by a process for producing agglomerates with a core/shell structure, in which i) initial agglomerates containing a first particulate solid are prepared; ii) a second particulate solid is agglomerated in the presence of the initial agglomerates with the addition of a binder liquid to give second stage agglomerates and, where appropriate, iii) an nth (where n is a positive integer xe2x89xa73) solid is agglomerated in the presence of the (nxe2x88x921)th stage agglomerates with the addition of a binder liquid to give nth stage agglomerates. Step iii) is optional. It can, if required, be repeated one or more times. The value of n starts at 3 and increases by 1 after every repetition.

Method for producing agglomerates comprising a core-shell structure


An electronic system having a backplane defining a plurality of slots each for demountably holding a respective one of a plurality of plug-in modules. The backplane includes a power trace extending to all of the slots for supplying power to all of the slots and a signal trace for carrying a daisy-chained signal to all of the slots. Associated with each of the slots is an arrangement for selectively bypassing the daisy-chained signal past the slot when no module is present in that slot. The arrangement comprises a controllable signal transmission device coupled to the signal trace for selectively providing a conductive path bypassing the slot and a current sensing switch coupled to a branch of the power trace which extends to the slot. The current sensing switch is responsive to current flow through the power trace to the slot for controlling the transmission device to close the conductive path in the absence of current flow and to open the conductive path in the presence of current flow.

This invention relates to electronic systems having a backplane for supporting plug-in modules wherein a signal is daisy-chained through the modules and, more particularly, to an arrangement in such a system for bypassing the daisy-chained signal when a module is absent from its assigned "slot" on the backplane.
Many electronic systems, such as computers, have a backplane (or mother board) on which are mounted connectors defining slots into which plug-in modules (or daughter cards) may be demountably secured. The backplane provides wiring (i.e., printed circuit traces) to effect communications between the modules and to provide a supply of power to the modules. Many such systems include a signal line on the backplane for carrying a daisy-chained signal through all of the modules present in the system. Since a given slot may or may not hold a module, some means must be provided for bypassing the daisy-chained signal around an empty slot and passing the daisy-chained signal through the slot when a module is present therein. Accordingly, it is an object of this invention to provide an arrangement for effecting such selective bypass function.
It is known to provide the selective bypass function by using manual or mechanical jumpering schemes. However, such schemes have proven to be unreliable. It is therefore a further object of this invention to provide a selective bypass arrangement which utilizes reliable non-mechanical devices.

Current sensing daisy-chain bypass arrangement


A system for dispensing a fluid includes a container including a sidewall defining an interior space for holding the fluid and configured to separate the fluid into a liquid and a vapor. The system also includes at least one fluid inlet disposed in the sidewall, at least one liquid outlet disposed in the sidewall, a first sensor, a second sensor, and a controller. The first sensor is positioned adjacent to or upstream of the at least one fluid inlet and configured to detect a first temperature of the fluid. The second sensor is positioned adjacent to or downstream of the at least one liquid outlet and configured to detect a second temperature of the fluid. The controller is configured to determine a fluid temperature differential based on the first and second temperatures and determine an operational status of the system based on the fluid temperature differential.

The field of this disclosure relates generally to systems for handling fluid. More particularly, this disclosure relates to systems for handling fluid for application to agricultural fields.
The agricultural industry commonly applies fluids, such as fertilizer, to fields during the cultivation of crops. Nitrogen rich chemicals are typically used as fertilizer, which is applied to soil to provide nutrients for plants. Anhydrous ammonia, for example, is a relatively dense nitrogen source commonly used as a fertilizer. However, anhydrous ammonia must be maintained within a pressure range to remain in liquid form. Additionally, anhydrous ammonia can pose a health risk to people who inhale the anhydrous ammonia. Therefore, anhydrous ammonia must be contained in proper pressure vessels that are strictly regulated. For example, regulations require the pressure vessels to be regularly pressure tested. Pressure testing is performed by filling the pressure vessels with water, which can cause the vessels to rust and otherwise deteriorate over time. The deterioration causes the formation of particulates and other loose materials within the pressure vessels. Sometimes, additives are added to the fluid to enhance desirable characteristics of the fluid. However, these additives can bond to particulates in the pressure vessels and, thereby, increase the size of the particulates. The particulates and other loose materials can become mixed in the fluid stored in the pressure vessels. As a result, when fluid application systems withdraw fluid from the pressure vessels for application to fields, the particulates in the fluid can cause the systems to operate inefficiently and improperly.
Typical pressure vessels include an outlet for withdrawing fluid from the pressure vessel. The fluid often includes liquid and vapor. Sometimes, vapor can flow through the outlet as liquid is withdrawn from the pressure vessel and result in misapplication of the fluid on the field. For example, when the pressure vessel is transported across uneven ground, the liquid can flow away from the outlet causing vapor to flow through the outlet and resulting in misapplication. Some pressure vessels include sensors to detect the fluid flow. However, these sensors typically do not detect this misapplication because the sensors detect the vapor flowing through the outlet. In addition, vapor in the pressure vessels can otherwise be ingested into the application system causing operating inefficiencies and damage to equipment. Moreover, modern fluid application systems have increased rates of application that exacerbate these problems.
Some fluid application systems include strainers for removing some materials from fluid. However, the strainers are not designed for handling volatile fluids used as fertilizer, such as anhydrous ammonia. Therefore, the strainers cause operating inefficiencies, misapplications, and increased maintenance time for the fluid application systems. For example, the strainers are often plugged by the particulates and additives contained in the fluids. Additionally, the strainers are difficult to clean and can pose safety risks to the operator when the operators have to clean the strainers.

This patent is subject to a terminal disclaimer.

Systems and methods for handling fluid for application to agricultural fields


A cable assembly includes a distribution cable, a tether cable, and a network access point (NAP) assembly having a cavity defined therein. The distribution cable includes optical fibers and the tether cable includes an optical fiber. The optical fiber of the tether cable is tightly constrained within the tether cable and portion thereof extends from the tether cable into the cavity of the NAP assembly and is spliced to a portion of one of the optical fibers of the distribution cable extending into the cavity of the NAP assembly from a side of the distribution cable. The splice is positioned in the cavity. Tight constraint of the optical fiber of the tether cable within the tether cable limits transmission of fiber movement to the portion of the optical fiber of the tether cable extending into the cavity of the NAP assembly, thereby protecting the splice.

Aspects of the present disclosure relate generally to fiber optic cable assemblies, such as those that include network access points where a communication element of a distribution cable is optically connected to a communication element of a tether cable that branches off from the distribution cable.
Some cable assemblies with network access points use a splice to connect optical fibers from a tether cable to optical fibers of a distribution cable. The optical fibers route signals from the distribution cable through the tether cable to a connector on an opposing end thereof. Typically excess length of the optical fibers of the tether cable is stored in a cavity within the network access point assembly. The excess fiber length allows the tether cable to be stretched and bent, where the excess fiber length then fills into the tether cable, as needed, to alleviate tension in the optical fiber and splice as a result of fiber movement resulting from the stretching and bending. However, for many cable assemblies the amount of excess optical fiber length stored in the cavity is related to the length of the respective tether cable. Longer tether cables require a greater amount of excess fiber length to compensate for stretching and a correspondingly longer cavity. This variation in cable assembly structure leads to manufacturing inefficiency and opens the door to potential manufacturing and design challenges, such as calculation of the amount of excess optical fiber length to be stored in the cavity.
A need exists for a fiber optic cable assembly, including a network access point, with structure or attributes that allow for a uniform length of excess fiber length to be stored in the cavity of a network access assembly without regard to the length of an associated tether cable.


A new and distinct cultivar of Aster plant named ‘Kiastlavmi’, characterized by its compact, upright, uniform and mounded plant habit; freely branching growth habit; semi-double type inflorescences with violet-colored ray florets; and tolerance to mildew.

The present invention relates to a new and distinct cultivar of Aster plant, botanically known as Aster dumosus and hereinafter referred to by the name 'Kiastlavmi'.
The objective of the breeding program is to create new compact Aster plants with uniform growth habit, freely branching habit, attractive and numerous ray florets and tolerance to mildew.
The new Aster plant originated from a cross-pollination in 2005, in Gensingen, Germany of Aster dumosus 'Kristina', not patented, as the female, or seed, parent with a proprietary selection of Aster dumosus identified as code number 08-15-4711, not patented, as the male, or pollen, parent. The new Aster plant was discovered and selected by the Inventor as a single flowering plant within the progeny of the stated cross-pollination in a controlled greenhouse environment in Gensingen, Germany in September, 2006.
Asexual reproduction of the new Aster plant by vegetative tip cuttings was first conducted in a controlled greenhouse environment in Gensingen, Germany in 2007. Asexual reproduction by vegetative tip cuttings has shown that the unique features of this new Aster plant are stable and reproduced true to type in successive generations.


A microwave activated gas generator in which microwave energy is supplied to an activated gas formation region through which a gas to be activated flows in a high-velocity stream. The stream is disturbed within or proximate the activation region to form a downstream stagnation region within the activated gas formation region to encourage microwave gas activation for efficiently coupling power to the gas to form a high-volume, high-velocity activated gas stream.

There are a variety of chemical vapor deposition (CVD) and etching processes, metallurgical applications and processes for melting high-temperature materials that involve the activation of a gas or gas mixture, and transport of the activated gas to a downstream region in which the plasma is employed to either react and condense to form a film of material on a substrate, react to etch the substrate material and many other uses. The gas may be activated by a number of means such as a hot filament, a microwave discharge, a DC discharge, and plasma jets or torches. In each of these processes, energy is transferred to the gas to create an activated gas containing ions, atoms, radicals, molecules, and/or electrons, many of which may be in excited states.
It is important that the desired activated species remain active until they reach the substrate in the downstream processing area. In microwave reactive gas generators, the gas is typically energized while passing through a microwave waveguide. The substrate to be processed is placed just downstream of the waveguide so that the species are in the useful activated state when they impinge on the substrate. The gas is typically either guided through the waveguide in a tube for activated gas downstream applications, or confined within and activated within a vacuum bell jar placed in the waveguide or a resonant chamber coupled to the waveguide.
In the apparatus employing a gas flow tube passing through the waveguide, the amount of energy that can be coupled to the gas is limited by the flow tube heating caused by heat transfer from the activated gas to the tube. Since the flow velocity is reduced at the tube walls, the gas proximate the walls tends to heat more quickly than the gas passing through the center of the tube, and the plasma discharge may even localize near the walls, thereby overheating the flow tube. Accordingly, such downstream microwave activation devices are able to couple only a relatively small amount of power to the flowing gas, making downstream processing rates slow.
In attempts to overcome this problem, there have been proposed systems requiring the use of metal electrodes in contact with the activation region. However, any electrode in close contact with the active gas leads to impurities and inefficiency.
One example of such a microwave gas activation device is disclosed in U.S. Pat. No. 4,767,608, issued on Aug. 30, 1988, to Matsumoto et al. The Matsumoto et al. patent discloses the generation of a plasma using electric discharges and microwaves, in which the plasma is expanded adiabatically to precipitate diamond-like carbon. The conducting electrodes in the plasma formation region lead to contamination of the plasma and so the end product, as well as decreasing the plasma formation efficiency due to the cooling of the gas by heat transfer to the electrodes.


A method for the production of aluminum hydroxide, including reacting water in the liquid phase and aluminum at a pH above about 12.4. In this pH range, aluminum hydroxide is produced at acceptable rates both for aluminum surface areas above 75,000 mm.sup.2 /g and for aluminum surface area of less than about 50,000 mm.sup.2 per gram, and even down to 20 mm.sup.2 per gram. According to an alternative view of the invention, it is characterized by the production of aluminum hydroxide by reacting aluminum with liquid water containing choline. Aluminum hydroxide particles having unique morphologies are obtained.

This invention relates to the production of aluminum trihydroxide.
U.S. Pat. No. 3,494,733 of Keith and Cornely, issued Feb. 10, 1970, for "Method for the Production of Alumina Trihydrate Dominant in Bayerite" emphasizes a "discovery that aluminum metal of high surface area and in a very fine state of subdivision, can be reacted with water at a basic pH to yield a predominantly trihydrate alumina without the need for extensive aging." As to the high surface area and very fine state of subdivision, Keith and Cornely state that the aluminum particles used in their process should have surface area lying in the range 75 thousand to 1 million square millimeters/gram.
Others have experimented with the reaction of aluminum metal with high pressure steam. See Tremper and Gordon, "Agglomeration Effects on the Sintering of Alumina Powders Prepared by Autoclaving Aluminum Metal" in "Ceramic Processing Before Firing", Onoda and Hench, pp. 153-76, John Wiley & Sons, N.Y. (1978).


The disclosed embodiments include a system and method for manufacturing an integrated computational element (ICE) core. The method comprises varying a distance between a thermal component relative to a substrate holder that holds at least one substrate during a thin film deposition process to improve uniformity of the ICE core. In one embodiment, varying the distance between the thermal component relative to the substrate holder that holds at least one substrate includes moving at least a portion of the substrate holder in at least one direction relative to the thermal component and also moving the thermal component in at least one direction relative to the substrate holder during the thin film deposition process.

In thin film deposition processes, the substrate, substrate platter, or substrate holder is almost always a flat platen. Due to the flat nature of the platen, non-uniformities in thickness are created in thermal deposition processes. The distance of the platen from the fixed evaporation source is less in the center than at the edge, and more material is deposited per unit time at the center than at the edge. For example, if the center of the source were placed directly under the rotating substrate platen, then a higher rate of deposition would be observed in the middle of the platen, with thinner layers observed on the edges.

Deposition of integrated computational elements (ICE) using a translation stage


The invention relates to an arrangement for removing unwanted hair and to a method of effecting such removal. Strips of sheet material of predetermined size and shape having a pressure sensitive adhesive and wax depliatory on one face thereof are placed in contact with the unwanted hair and then pulled away therefrom, removing the unwanted hair therewith.

Selective hair removal, for example for the shaping of eye brows, is very difficult and can be painful.
This is generally accomplished by tweezing or plucking because the use of depilatories is too difficult to control for use where shaping of the hair line is desired.
Attempts have been made to use hot wax for hair removal and shaping. This, however, can be painful and in addition requires professional application.


A problem to be solved by the present invention is to provide a substance having an effect of increasing intracellular ATP and, particularly, a potent ATP enhancer far surpassing the increasing effect of inosine or febuxostat alone.

ATP (adenosine triphosphate, hereinafter sometimes simply referred to as ATP) is the most important compound that stores energy of living organisms and supplies the energy when necessary, and it is considered that ATP reduction is related to pathological conditions of various diseases. For example, with regard to the causes of various types of hereditary hemolytic anemia, ATP reduction in erythrocytes is considered as a mechanism of hemolysis. Examples include sickle cell disease (Non-Patent Document 1), pyruvate kinase deficiency (Non-Patent Document 2), spherocytosis (Non-Patent Document 3), elliptocytosis (Non-Patent Document 3), stomatocytosis (Non-Patent Document 4), thalassemia (Non-Patent Document 5), etc.
Additionally, intracellular ATP reduction is suggested as a mechanism of myocardial damage due to ischemic heart disease (Non-Patent Document 6), and it is reported that symptoms of chronic stable angina were suppressed by high-dose administration of a xanthine oxidase/xanthine dehydrogenase inhibitor, allopurinol (Non-Patent Document 7). The authors suggested that an increase in ATP due to allopurinol had a favorable effect on ischemic heart disease (Non-Patent Document 7).
Furthermore, an ATP enhancement therapy is likely to be effective for heart failure. Heart failure patients often undergo heart transplantation in US and, instead of a period from occurrence of heart failure to death, a period from occurrence of heart failure to heart transplantation is used as a measure of a speed of progress of heart failure. A short period until heart transplantation indicates that the progress of heart failure is fast. In Europe and US, the frequency of hereditary muscle AMP deaminase (AMPD) deficiency is extremely high, and about 20% of the general population has heterozygous deficiency. It is known from studies that people with muscle genetic AMPD deficiency have a longer period from heart failure to heart transplantation (Non-Patent Document 8). It is also suggested that an AMPD inhibitor improves heart failure in mice (Non-Patent Document 9). Generally, ATP of muscle decreases due to exercise. However, it is reported that people with hereditary muscle AMPD deficiency have intramuscular ATP not decreasing, or restrained from decreasing, after exercise (Non-Patent Document 10). Specifically, since AMP is not converted into IMP (inosine monophosphate, hereinafter sometimes simply referred to as IMP), AMP reduction can be prevented and ATP reduction does not occur (FIG. 1). From above, it is considered that genetic muscle AMPD deficiency was less likely to cause ATP reduction in cardiomyocytes and suppressed the progress of heart failure.
It can be expected that enhancing ATP in this way improves pathological conditions of diseases in which a decrease in ATP relates to the pathological conditions.
Although it is reported that inosine enhances muscular movement in expectation of occurrence of an enhancing action on muscular movement due to ATP increased by administration of inosine, a report denying the effect thereof is also made recently (Non-Patent Document 11). However, it is possible that a cause of inability to prove inosine's muscular enhancing action is because inosine alone is not sufficient for completing the ATP enhancing action.
Nishino et al. have found that a xanthine oxidase/xanthine dehydrogenase inhibitor such as febuxostat administered to a model mouse of amyotrophic lateral sclerosis (hereinafter sometimes simply referred to as ALS) inhibits disease progression (Non-Patent Document 12). Allopurinol did not inhibit the disease progression. Nishino et al. speculate that an increase in ATP of nerve cells due to administration of febuxostat suppresses disease progression (Non-Patent Document 12). Nishino et al. speculate that a reason that allopurinol does not have an effect is because allopurinol consumes PRPP and inhibits ATP synthesis to the contrary (Non-Patent Document 12). In fact, it is reported that knock-down of Na/K-ATPase in ALS model mice suppressed degeneration of nerve cells (Non-Patent Document 12). It is also reported that Na/K-ATPase activity is increased in ALS patients (Non-Patent Document 13). Therefore, it is considered that activation of Na/K-ATPase that reduces ATP promotes the onset or progression of ALS and that suppression of Na/K-ATPase that suppresses ATP reduction suppresses the progress of ALS.
Furthermore, it is reported that administration of inosine alleviates symptoms of Parkinson's disease (Non-Patent Document 14) and multiple sclerosis (Non-Patent Document 15). The authors of both documents believe that a decrease in serum uric acid value may be related to the diseases. Clinical trials are conducted for the purpose of raising the serum uric acid value by administering inosine, and producing a therapeutic effect. However, the effect is not enough in the past reports.
It has been reported that intracellular ATP somewhat increases due to single administration of inosine. In fact, Ogasawara et al. reported that ATP increased when erythrocytes allowed to stand at low temperature for 20 to 30 days and reduced in ATP were allowed to stand for one hour after addition of inosine (Non-Patent Document 16). However, inosine is rapidly metabolized in human bodies through hypoxanthine and xanthine to uric acid (FIG. 1). Therefore, inosine alone was insufficient to produce the sufficient ATP enhancing action. Additionally, although single administration of febuxostat is expected to somewhat enhance intracellular ATP, this alone may be insufficient.

Abstract: A human or animal intracellular ATP enhancer comprising a combination of A) and B):                A) a xanthine oxidase/xanthine dehydrogenase inhibitor or a pharmaceutically acceptable salt thereof; and        B) any one or more compounds selected from inosine, inosinic acid, hypoxanthine, and pharmaceutically acceptable salts thereof.