Telemetric differential pressure sensing method
First Claim
1. A method for remotely detecting in vivo pressure, said method comprising the steps of:
- (a) implanting in a living body a differential pressure sensor comprising;
(1) a housing having means defining an opening extending therethrough;
(2) flexible diaphragm means extending across said housing opening and being secured with respect to said housing, said diaphragm means communicating with pressures in two separate regions external to the sensor with the pressure in one of the regions being an internal bodily pressure when the sensor is implanted in a living body;
(3) means for defining a mechanical contact reference position of said flexible diaphragm means with respect to said housing; and
,(4) means having a preselected, detectable parameter, the preselected, detectable parameter being detectable by detection means located outside the living body, said means having a preselected, detectable parameter being at least in part cooperatively connected to and movable with said flexible diaphragm means so that said preselected detectable parameter will change with movement of said flexible diaphragm means, such that the value of said preselected, detectable parameter changes as a known function of the displacement of said flexible diaphragm means from the reference position, said displacement being a known function of the differences in the external pressures on said flexible diaphragm means;
(b) calibrating the implanted sensor by;
(1) manipulating the sensor through the intact skin of the body to cause the flexible diaphragm means to assume the mechanical contact reference position;
(2) remotely detecting the value of the preselected, detectable parameter when the flexible diaphragm means is at the mechanical contact reference position;
(3) terminating the manipulation of the sensor; and
,(c) thereafter remotely detecting any change in the value of the preselected, detectable parameter from the value at the mechanical contact reference position, said detecting being accomplished without any connection to the sensor which requires a break in the skin, whereby a change in said value represents the difference in pressures on the flexible diaphragm means.
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Accused Products
Abstract
A differential pressure sensing device is fully implanted in the body of a patient to monitor internal pressure such as intracranial pressure. A movable element in the sensor communicates with the internal pressure of the body to be measured on one side and the atmospheric pressure on the other, the latter communicated through the intact skin and a nearly coplanar membrane. The movable element'"'"'s differential pressure dependent displacement changes a physical characteristic of the sensor, such as the resonant frequency of a tuned L-C circuit, and the change is detected external to the body by a radiating detector system, such as a frequency swept radio frequency oscillator, by which the internal pressure is read out.
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Citations
18 Claims
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1. A method for remotely detecting in vivo pressure, said method comprising the steps of:
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(a) implanting in a living body a differential pressure sensor comprising; (1) a housing having means defining an opening extending therethrough; (2) flexible diaphragm means extending across said housing opening and being secured with respect to said housing, said diaphragm means communicating with pressures in two separate regions external to the sensor with the pressure in one of the regions being an internal bodily pressure when the sensor is implanted in a living body; (3) means for defining a mechanical contact reference position of said flexible diaphragm means with respect to said housing; and
,(4) means having a preselected, detectable parameter, the preselected, detectable parameter being detectable by detection means located outside the living body, said means having a preselected, detectable parameter being at least in part cooperatively connected to and movable with said flexible diaphragm means so that said preselected detectable parameter will change with movement of said flexible diaphragm means, such that the value of said preselected, detectable parameter changes as a known function of the displacement of said flexible diaphragm means from the reference position, said displacement being a known function of the differences in the external pressures on said flexible diaphragm means; (b) calibrating the implanted sensor by; (1) manipulating the sensor through the intact skin of the body to cause the flexible diaphragm means to assume the mechanical contact reference position; (2) remotely detecting the value of the preselected, detectable parameter when the flexible diaphragm means is at the mechanical contact reference position; (3) terminating the manipulation of the sensor; and
,(c) thereafter remotely detecting any change in the value of the preselected, detectable parameter from the value at the mechanical contact reference position, said detecting being accomplished without any connection to the sensor which requires a break in the skin, whereby a change in said value represents the difference in pressures on the flexible diaphragm means.
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2. A method for remotely detecting in vivo pressure, said method comprising the steps of:
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(a) implanting in a living body a differential pressure sensor comprising; (1) a housing having means defining an opening extending therethrough; (2) flexible diaphragm means extending across said housing opening and being secured with respect to said housing, said flexible diaphragm means communicating with pressures in two separate regions external to the sensor with the pressure in one of the regions being an internal bodily pressure when the sensor is implanted in a living body; (3) means for defining a mechanical contact reference position of said flexible diaphragm means with respect to said housing, said mechanical contact reference position corresponding to a known pressure relationship between the pressures in the two separate regions; and (4) means having a preselected, detectable parameter, the preselected, detectable parameter being detectable by detection means located outside the living body, said means having a preselected, detectable parameter being at least in part cooperatively connected to and movable with said flexible diaphragm means so that said preselected detectable parameter will change with movement of said flexible diaphragm means, such that the value of said preselected, detectable parameter changes as a known function of the displacement of said flexible diaphragm means from the mechanical contact reference position, said displacement being a known function of the difference in the external pressures on said flexible diaphragm means; (b) calibrating the implanted sensor by; (1) manipulating the sensor to cause the flexible diaphragm means to assume the mechanical contact reference position; (2) remotely detecting the value of the preselected, detectable parameter when the flexible diaphragm means is at the mechanical contact reference position; (3) terminating the manipulation of the sensor; and
,(c) thereafter remotely detecting any change in the value of the preselected, detectable parameter from the value at the mechanical contact reference position, said detecting being accomplished without any connection to the sensor which requires a break in the skin, whereby a change in value represents the difference in pressures on the flexible diaphragm means.
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3. A method for measuring an in vivo pressure, said method comprising the steps of:
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(a) implanting in a living body a differential pressure sensor comprising; (1) a housing having an opening therein; (2) a flexible diaphragm means having a first side and a second side, said flexible diaphragm means extending across said housing opening and being secured with respect to said housing so that when the sensor is implanted in the living body, the first side of said flexible diaphragm means is in pressure communication with an internal bodily pressure to be measured and the second side of said flexible diaphragm means is in mechanical pressure communication with the interior side of a portion of skin and thereby in pressure communication across the intact skin with atmospheric pressure external to the living body on the exterior side of the portion of skin, whereby the motion of said flexible diaphragm means is responsive to the changes in the difference between said internal bodily pressure and atmospheric pressure on said exterior side of the portion of skin whereby the sensor is compensated for said atmospheric pressure; (3) means defining a mechanical contact reference position with respect to said housing of said flexible diaphragm means, said mechanical contact reference position corresponding to a known pressure relationship between the pressures in the two separate regions; (4) means having a preselected, detectable parameter, the preselected, detectable parameter being detectable by detection means located outside the living body, said means having a preselected, detectable parameter being at least in part cooperatively connected to and movable with said flexible diaphragm means so that said preselected detectable parameter will change with movement of said flexible diaphragm means, such that the value of said preselected, detectable parameter is detectable by detection means external to said living body, said preselected, detectable parameter changing as a known function of changes in said difference of pressures on said flexible diaphragm means from the predetermined pressure relationship at said mechanical contact reference position; (b) calibrating the implanted sensor by; (1) manipulating the sensor through the intact skin of the body to cause the flexible diaphragm means to assume said mechanical contact reference position; (2) remotely detecting the value of the preselected, detectable parameter when the flexible diaphragm means is at said mechanical contact reference position; (3) termination of the manipulation of the sensor; and
,(c) thereafter remotely detecting any change in the value of the preselected, detectable parameter from the value at the mechanical contact reference position by the external detection means, said detecting being accomplished without any connection to the sensor which requires a break in the skin, whereby a change in value is related to the difference in said pressures on said flexible diaphragm means. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for remotely detecting in vivo pressure, said method comprising the steps of:
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a. implanting in a living body a differential pressure sensor comprising; (1) a housing having means defining an opening extending therethrough; (2) flexible diaphragm means extending across said housing opening and being secured with respect to said housing;
said flexible diaphragm means communicating with pressures in two separate regions external to the sensor that are separated by the flexible diaphragm means with the pressure in one of the regions being an internal bodily pressure when the sensor is implanted in a living body;(3) means for defining a reference position of said flexible diaphragm means with respect to said housing; and
,(4) means having a preselected, detectable variable parameter that is a known function of the displacement of said flexible diaphragm means from the reference position, said displacement being a known function of the differences in the external pressures on said flexible diaphragm means; b. calibrating the implanted sensor by; (1) manipulating the sensor through the intact skin of the body to cause the sensor to assume the reference position; (2) remotely detecting the value of the variable parameter when the sensor is in the reference position; (3) terminating the manipulation of the sensor; c. thereafter remotely detecting any change in the value of the variable parameter from the value at the reference position without any connection to the sensor which requires a break in the skin, said change in value representing the differences in pressures on the flexible diaphragm means of the sensor.
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18. A method for remotely detecting in vivo pressure, said method comprising the steps of:
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a. implanting in a living body a differential pressure sensor comprising; (1) a housing having means defining an opening extending therethrough; (2) flexible diaphragm means extending across said housing opening and being secured with respect to said housing;
said flexible diaphragm means communicating with pressures in two separate regions external to the sensor that are separated by the flexible diaphragm means with the pressure in one of the regions being an internal bodily pressure when the sensor is implanted in a living body;(3) means for defining a reference position of said flexible diaphragm means with respect to said housing; and
,(4) means having a preselected, detectable variable parameter that is a known function of the displacement of said flexible diaphragm means from the reference position, said displacement being a known function of the differences in the external pressures on said flexible diaphragm means; b. calibrating the implanted sensor by; (1) manipulating the sensor to cause the sensor to assume the reference position; (2) remotely detecting the value of the variable parameter when the sensor is in the reference position; (3) terminating the manipulation of the sensor; c. thereafter remotely detecting any change in the value of the variable parameter from the value at the reference position without any connection to the sensor which requires a break in the skin, said change in value representing the difference in pressures on the flexible diaphragm means of the sensor.
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Specification