Multipoint pressure-sensing catheter system
First Claim
1. A multipoint pressure sensing catheter system, comprising:
- a catheter;
a plurality of pressure sensors spaced along the catheter; and
signal conduit means within the catheter for providing a path for signals to be passed between an external monitor and each of the pressure sensors, the signal conduit means including only two electrical conductors which extend between the pressure sensors and are connectable to the external monitor,the pressure sensors each including pressure transducer means for converting a sensed pressure into an internal signal, switching means for applying the internal signal to the signal conduit means, and means responsive to a command signal from the external monitor for selectively activating the switching means at a distinct interval of time,whereby the external monitor may receive separately in time the internal signal generated by each of the pressure sensors.
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Accused Products
Abstract
A capacitive pressure sensor suitable for making highly sensitive, low pressure measurements is disclosed. The sensor may be mounted into a 0.5 mm OD catheter suitable for multipoint pressure measurements from within the coronary artery of the heart. The sensor employs a transducer which consists of a rectangular bulk silicon micro-diaphragm several hundred microns on a side by two microns thick, surrounded by a supporting bulk silicon rim about 12 microns thick. Both the diaphragm and the rim are defined by a double diffusion etch-stop technique. The transducer fabrication process features a batch wafer-to-glass electrostatic seal followed by a silicon etch, which eliminates handling of individual small diaphragm structures until die separation and final packaging. An addressable read-out interface circuit may be used with the sensor to provide a high-level output signal, and allows the sensor to be compatible for use on a multisite catheter having only two electrical leads.
249 Citations
22 Claims
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1. A multipoint pressure sensing catheter system, comprising:
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a catheter; a plurality of pressure sensors spaced along the catheter; and signal conduit means within the catheter for providing a path for signals to be passed between an external monitor and each of the pressure sensors, the signal conduit means including only two electrical conductors which extend between the pressure sensors and are connectable to the external monitor, the pressure sensors each including pressure transducer means for converting a sensed pressure into an internal signal, switching means for applying the internal signal to the signal conduit means, and means responsive to a command signal from the external monitor for selectively activating the switching means at a distinct interval of time, whereby the external monitor may receive separately in time the internal signal generated by each of the pressure sensors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A catheter system including a plurality of pressure sensors, the system comprising:
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a catheter; a plurality of pressure sensors spaced along the catheter; and means disposed within the catheter for providing a path for signals to be passed between an external monitoring apparatus and each of the pressure sensors, each of the pressure sensors including an ultraminiature capactive pressure transducer having an integrally formed structure made from single-crystal material and that has a diaphragm and a rim extending about a substantial portion of the periphery of the diaphragm, the structure having at least two overall dimensions orthogonal to one another that are less than one millimeter. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A multipoint pressure-sensing catheter system, comprising:
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a catheter; a plurality of pressure-sensing apparatuses spaced along the catheter; and signal conduit means within the catheter for providing a path for electrical signals to be passed between an external monitor and each of the pressure sensing apparatuses; the pressure sensing apparatuses each including pressure transducer means for converting a sensed pressure into a first electrical signal, switching means for applying the first electrical signal to the signal conduit means, and addressing means responsive to command signals in the form of temporary changes in power supply voltage from the external monitor for selectively activating the switching means at a distinct interval of time. the signal conduit means including no more than two electrical conductors which provide electrical power to and extend between the pressure sensing apparatuses and are connectable to the external monitor, the pressure transducer means in each pressure sensing apparatus including a transducer capacitor responsive to pressure changes applied thereto, the switching means of each pressure sensing apparatus including means for discharging the transducer capacitor thereof when a voltage upon the such capacitor reaches a predetermined level, whereby the external monitor can address each pressure sensing apparatus separately in time, and receive separately in time the first electrical signal generated by each pressure sensing apparatus by providing such command signals over the two electrical conductors. - View Dependent Claims (19, 20, 21, 22)
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Specification