초록 ▼

A biventricular cardiac prosthesis has a flow balance control system to balance blood flow through the left and right sides of the prosthesis to maintain a patient's left atrial pressure within physiologic bounds. The prosthesis can be configured to have flow characteristics so that a signal represe

A biventricular cardiac prosthesis has a flow balance control system to balance blood flow through the left and right sides of the prosthesis to maintain a patient's left atrial pressure within physiologic bounds. The prosthesis can be configured to have flow characteristics so that a signal representative of the difference in hydraulic pumping pressures on the left and right sides of the prosthesis is representative of the difference between left and right atrial pressures of a patient having the prosthesis implanted. This signal can be used as a control signal to drive the prosthesis so that left atrial pressure is approximately equal to right atrial pressure, and within physiologic bounds. A specific prosthesis includes left and right pumping sections, each having a blood pumping chamber and a hydraulic fluid chamber, with a reciprocating hydraulic pump driving systole alternately on the right and left sides. A hydraulic balance chamber is hydraulically coupled to the right hydraulic fluid chamber and an adjustable occluder varies flow resistance through the hydraulic coupling. The occluder can be adjusted based on the control signal to adjustably derate right side blood flow to achieve the desired pressure balance, or the occluder can be adjusted based on fluid communication with sources of pressure in the prosthesis that are representative of right and left atrial pressures.

대표청구항 ▼

A biventricular cardiac prosthesis has a flow balance control system to balance blood flow through the left and right sides of the prosthesis to maintain a patient's left atrial pressure within physiologic bounds. The prosthesis can be configured to have flow characteristics so that a signal represe

A biventricular cardiac prosthesis has a flow balance control system to balance blood flow through the left and right sides of the prosthesis to maintain a patient's left atrial pressure within physiologic bounds. The prosthesis can be configured to have flow characteristics so that a signal representative of the difference in hydraulic pumping pressures on the left and right sides of the prosthesis is representative of the difference between left and right atrial pressures of a patient having the prosthesis implanted. This signal can be used as a control signal to drive the prosthesis so that left atrial pressure is approximately equal to right atrial pressure, and within physiologic bounds. A specific prosthesis includes left and right pumping sections, each having a blood pumping chamber and a hydraulic fluid chamber, with a reciprocating hydraulic pump driving systole alternately on the right and left sides. A hydraulic balance chamber is hydraulically coupled to the right hydraulic fluid chamber and an adjustable occluder varies flow resistance through the hydraulic coupling. The occluder can be adjusted based on the control signal to adjustably derate right side blood flow to achieve the desired pressure balance, or the occluder can be adjusted based on fluid communication with sources of pressure in the prosthesis that are representative of right and left atrial pressures. kground sounds to be outputted from respective ones of the sound output units at the output ratio calculated by the output ratio calculating unit. 4. A video game apparatus according to claim 1, wherein the output ratio of the background sounds is calculated using a correction coefficient which is set in advance for each of the background sounds in addition to said ratio between the first distance and the second distance. 5. A video game apparatus according to claim 1, wherein the output ratio of the background sounds is calculated based on said first distance and said second distance in addition to said ratio between the first distance and the second distance. 6. A background sound output setting method in a video game in which a specified event is executed in a game space displayed on a monitor, and a plurality of background sounds having different attributes are outputted at a specified output ratio from a plurality of sound output units spaced apart from each other, comprising the steps of: reading the background sound data from a recording unit for storing the plurality of background sounds having different attributes, outputting the read background sound data as background sounds from the plurality of sound output units, and setting the output ratio of levels the background sounds output from at least two of the sound output units based on a relationship of a viewing point and a viewing direction to at least two virtual sound sources, each producing same ones of the background sounds, in the game space, wherein the output ratio of the background sounds is calculated in accordance with a ratio between a first distance and a second distance where said first distance is a space between the viewing point and a first one of the virtual sound sources and a second distance is a space between the viewing point and a second one of the virtual sound sources. 7. A background sound output setting method according to claim 6, wherein the output ratio of the background sounds to be output from the sound output units is also calculated according to a corresponding one of the attributes, and a volume of the background sound to be output from the respective sound output units is set at the output ratio. 8. A background sound output setting method according to claim 6, wherein the attributes of the background sounds are characterized by frequencies thereof, and the output ratios of ones of the background sounds including one of high-frequency sound components and low-frequency sound components vary less than other ones of the background sounds including intermediate-frequency sound components. 9. A computer readable recording medium storing a background sound output setting program in a video game in which a specified event is executed in a game space displayed on a monitor, and a plurality of background sounds having different attributes are outputted at a specified output ratio from a plurality of sound output units spaced apart from each other, wherein the output ratio of the background sounds output from at least two of the sound output units is set based on a relationship a viewing point and a viewing direction to at least two virtual sound sources, each producing same ones of the background sounds, in the game space while background sound data of the background sounds is read from a recording unit and output from the plurality of sound output units, wherein the output ratio of the background sounds is calculated in accordance with a ratio between a first distance and a second distance where said first distance is a space between the viewing point and a first one of the virtual sound sources and a second distance is a space between the viewing point and a second one of the virtual sound sources. 10. A computer readable recording medium according to claim 9, wherein the output ratio of the background sounds to be output from the sound output units is also calculated according to a corresponding one of the attributes, and