Adapter cable for connecting a pulsoximetry sensor unit to a medical measuring device

Claim 2

An adapter cable for connecting a pulsoximetry sensor unit to a medical measuring device, said pulsoximetry sensor unit comprising two antiparallel-connected, light-emitting elements for emitting light of different wavelengths into a part of the body supplied with pulsating blood and a photosensitive element for receiving light which has been allowed to pass through said part of the body supplied with pulsating blood, and said medical measuring device providing a pulsed supply signal, which supplies power to the light-emitting elements, and determining, on the basis of a signal produced by said photosensitive element, the oxygen saturation of the hemoglobin contained in the blood of the transilluminated part of the body, wherein said adapter cable comprises the following features; first and second lines for connecting the antiparallel-connected, light-emitting elements with supply terminals of the medical measuring device; a third line for connecting one terminal of the photosensitive element to a measuring signal input of the medical measuring device; a first grounding line for connecting another terminal of the photosensitive element to a reference potential terminal of the measuring device; an electronic switch means, which is connected to said first and second lines and which, when activated, forms a shunt to at least one of the light-emitting elements, and a fault current detection circuit, which detects current flowing through the first grounding line and for activating the electronic switch means, if the current flowing through said first grounding line exceeds a limit value.

Claim 3

An adapter cable for connecting a pulsoximetry sensor unit to a medical measuring device, said pulsoximetry sensor unit comprising two antiparallel-connected, light-emitting elements for emitting light of different wavelengths into a part of the body supplied with pulsating blood and a photosensitive element for receiving light which has been allowed to pass through said part of the body supplied with pulsating blood, and said medical measuring device providing a pulsed supply signal, which supplies power to the light-emitting elements, and determining, on the basis of a signal produced by said photosensitive element, the oxygen saturation of the hemoglobin contained in the blood of the transilluminated part of the body, wherein said adapter cable comprises the following features: first and second lines for connecting the antiparallel-connected, light-emitting elements with supply terminals of the medical measuring device; a third line for connecting one terminal of the photosensitive element to a measuring signal input of the medical measuring device; a fourth line for connecting another terminal of the photosensitive element to a first node; a first resistor connecting the first node to a second node; a fifth line for connecting the second node to a reference potential terminal of the medical measuring device; an electronic switch means, which is connected at least to one of said first or second lines in such a way that, when said electronic switch means is activated, a flow of limit-exceeding current through the light-emitting elements will be prevented, and a fault current detection circuit, having an input side connected to said first and second nodes and having an output side connected to said electronic switch means and responsive to a voltage drop across the first resistor exceeding a limit value so as to activate said electronic switch means.

Claim 4

An adapter cable for connecting a pulsoximetry sensor unit to a medical measuring device, said pulsoximetry sensor unit comprising two antiparallel-connected, light-emitting elements for emitting light of different wavelengths into a part of the body supplied with pulsating blood and a photosensitive element for receiving light which has been allowed to pass through said part of the body supplied with pulsating blood, and said medical measuring device providing a pulsed supply signal, which supplies power to the light-emitting elements, and determining, on the basis of a signal produced by said photosensitive element, the oxygen saturation of the hemoglobin contained in the blood of the transilluminated part of the body, wherein said adapter cable comprises the following features: first and second lines for connecting the antiparallel-connected, light-emitting elements with supply terminals of the medical measuring device; a third line for connecting one terminal of the photosensitive element to a measuring signal input of the medical measuring device; a fourth line for connecting another terminal of the photosensitive element to a first node; a first resistor connecting the first node to a second node; a fifth line for connecting the second node to a reference potential terminal of the medical measuring device; an electronic switch means, which is connected at least to one of said first or second lines in such a way that, when said electronic switch means is activated, a flow of limit-exceeding current through the light-emitting elements will be prevented, and a fault current detection circuit, having an input side connected to said first and second nodes and having an output side connected to said electronic switch means and responsive to a voltage drop across the first resistor exceeding a limit value so as to activate said electronic switch means.

Claim 5

An adapter cable according to claim 2, wherein the electronic switch means is connected to said first and second lines in parallel connection to the light-emitting elements so as to form, when activated, a shunt to at least one of said light-emitting elements.

Claim 6

An adapter cable according to claim 2, wherein said electronic switch means is a self-holding circuit, which responds to the voltage across the first resistor exceeding a limit value only if the medical measuring device applies to said first and second lines potentials suitable for activating a predetermined light-emitting element among the two light-emitting elements.

Claim 7

An adapter cable for connecting a pulsoximetry sensor unit to a medical measuring device, said pulsoximetry sensor unit comprising two antiparallel-connected, light-emitting elements for emitting light of different wavelengths into a part of the body supplied with pulsating blood, a photosensitive element for receiving light which has been allowed to pass through said part of the body supplied with pulsating blood, and a coding resistor whose resistance value is representative of the wavelength of the light emitted by one of said light-emitting elements, and said medical measuring device providing a pulsed supply signal, which supplies power to the light-emitting elements, and determining, on the basis of a signal produced by said photosensitive element, the oxygen saturation of the hemoglobin contained in the blood of the transilluminated part of the body, wherein said adapter cable comprises the following features: first and second lines for connecting the antiparallel-connected, light-emitting elements with supply terminals of the medical measuring device; a third line for connecting one terminal of the photosensitive element to a measuring signal input of the medical measuring device; a first grounding line for connecting another terminal of the photosensitive element to a first node; a coding resistor connection line for connecting one terminal of the coding resistor to a coding resistor terminal of the measuring device; a second grounding line for connecting another terminal of the coding resistor to the first node; a third grounding line constructed as an outer shield of the adapter cable and connected to the first node; a first resistor connecting said first node to a second node; a fifth line for connecting the second node to a reference potential terminal of the measuring device; an electronic switch means connected to said first and second lines and forming, when activated, a shunt for at least one of the light-emitting elements; and a fault current detection circuit, which responds to a voltage drop across the first resistor exceeding a limit voltage, so as to activate said electronic switch means.

Claim 8

An adapter cable for connecting a pulsoximetry sensor unit to a medical measuring device, said pulsoximetry sensor unit comprising two antiparallel-connected, light-emitting elements for emitting light of different wavelengths into a part of the body supplied with pulsating blood, a photosensitive element for receiving light which has been allowed to pass through said part of the body supplied with pulsating blood, and a coding resistor whose resistance value is representative of the wavelength of the light emitted by one of said light-emitting elements, and said medical measuring device providing a pulsed supply signal, which supplies power to the light-emitting elements, and determining, on the basis of a signal produced by said photosensitive element, the oxygen saturation of the hemoglobin contained in the blood of the transilluminated part of the body, wherein said adapter cable comprises the following features: first and second lines for connecting the antiparallel-connected, light-emitting elements with supply terminals of the medical measuring device; a third line for connecting one terminal of the photosensitive element to a measuring signal input of the medical measuring device; a first grounding line for connecting another terminal of the photosensitive element to a first node; a coding resistor connection line for connecting one terminal of the coding resistor to a coding resistor terminal of the measuring device; a second grounding line for connecting another terminal of the coding resistor to the first node; a third grounding line constructed as an outer shield of the adapter cable and connected to the first node; a first resistor connecting said first node to a second node; a fifth line for connecting the second node to a reference potential terminal of the measuring device; an electronic switch means connected to said first and second lines and forming, when activated, a shunt for at least one of the light-emitting elements; and a fault current detection circuit, which responds to a voltage drop across the first resistor exceeding a limit voltage, so as to activate said electronic switch means.

Claim 9

An adapter cable according to claim 5, comprising, in addition, a third resistor for compensation of a falsification of a coding resistor resistance value detected by the medical measuring device, said falsification being caused by the first resistor, wherein said third resistor has one terminal connected to the coding resistor connection line, another terminal of said third resistor adapted to be connected to the reference potential terminal of the medical measuring device.

Claim 10

An adapter cable according to claim 6, wherein said third resistor has a resistance value R3, which satisfies the following condition: 100 kilo-ohm<R3<10 mega-ohm.

Claim 11

An adapter cable according to one of the claims 1, 2 or 5, wherein said electronic switch means is a series connection, which is connected between the first line and the second line and which comprises a diode and a transistor whose emitter-collector path is in series with said diode.

Claim 12

An adapter cable according to one of claims 1, 2 or 5, wherein the fault current detection circuit comprises two transistors in thyristor connection.