Patent EP0194105A2 successfully refreshed from Google Patents.
EP0194105A2
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EP
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Oximeter
Assignee: Messer LLC
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Filing: 1986-02-27
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Granted: —
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Expires: 2006-02-27
Abstract
Abstract An oximeter includes a probe 100 having LEDS 101, 102, for transmitting light of at least two different wavelengths and a photo-sensing diode 103 for transducing the light from the LEDS 101, 102 into signals. Means is provided for producing a plurality of signals comprising DC and AC component signals corresponding to the attenuation of the transmitted light at the different wavelengths. Data processing means is provided which is responsive to the signals for determining the oxygen saturation SaO 2 through the medium e.g. blood containing tissue through which the light is transmitted.
Inventors
- 👤 Robert A. Nichols
- 👤 Jonas A. Pologe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 09:02
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/145; A61B5/1455; A61B5/14551; A61B5/74; A61B5/7475; G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/314; G01N21/3151; G01N2021/3144; G01N2021/3181
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
187 words
An oximeter including probe means 100 having light-emitting means 101, 102 for transmitting light of at least two different wavelengths through blood-containing tissue, sensing means 103 for transducing said transmitted light into signals, means for producing a plurality of signals corresponding to the attenuation of said transmitted light at the different wavelengths, said plurality of signals comprising DC and AC component signals, and data processing means responsive to said signals for determining the oxygen saturation Sa0 2 in said tissue is characterized in that said oximeter further comprises variable drive control means 254, 256 for controlling said light-emitting means 101, 102 to optimize analog-to digital conversion and assure sufficient light emission, said signal-producing means comprising variable gain amplifier means 152, 190 for applying said signals to said data processing means, and said data processing means comprising means 158, 210 for controlling the gain of said variable gain amplifier means 152, 190 and means for normalizing said AC signals developed from each of said different wavelengths by computing the ratio of said AC signal amplitude at a predetermined phase angle to said DC signal amplitude for each wavelength.
Claim 2
Dependent Claim
187 words
An oximeter including probe means 100 having light-emitting means 101, 102 for transmitting light of at least two different wavelengths through blood-containing tissue, sensing means 103 for transducing said transmitted light into signals, means for producing a plurality of signals corresponding to the attenuation of said transmitted light at the different wavelengths, said plurality of signals comprising DC and AC component signals, and data processing means responsive to said signals for determining the oxygen saturation Sa0 2 in said tissue is characterized in that said oximeter further comprises variable drive control means 254, 256 for controlling said light-emitting means 101, 102 to optimize analog-to digital conversion and assure sufficient light emission, said signal-producing means comprising variable gain amplifier means 152, 190 for applying said signals to said data processing means, and said data processing means comprising means 158, 210 for controlling the gain of said variable gain amplifier means 152, 190 and means for normalizing said AC signals developed from each of said different wavelengths by computing the ratio of said AC signal amplitude at a predetermined phase angle to said DC signal amplitude for each wavelength.
Claim 3
Dependent Claim
106 words
An oximeter as claimed in claim 1, characterized in that said variable gain amplifier means comprises a first variable gain amplifier 152 connected to be controlled in gain by said data processing means 150, 154, 156 applying said signals from said sensing means 103 to said first variable gain amplifier 152, means connected to the output of said first variable gain amplifier 152 for separating the DC and AC components thereof, a second variable gain amplifier 190 connected to receive the AC output of said first variable gain amplifier 152, said data processing means 210, 212 controlling the gain of said second variable gain amplifier 190.
Claim 4
Dependent Claim
142 words
An oximeter including probe means 100 having means for transmitting light of at least two different wavelengths through blood-containing tissue, sensing means 103 for transducing said transmitted light into signals, means for producing a plurality of signals corresponding to the attenuation of said transmitted light at the different wavelengths, data processing means responsive to said signals for determining the oxygen saturation Sa0 2 of blood in said tissue, and a power supply for said oximeter adapted to convert power at a power supply frequency; is characterised in that said means for producing a plurality of signals comprises means for sampling said signals at a sampling frequency and means for adjusting said sampling frequency to maintain an integer ratio between said power supply frequency and said sampling frequency such that sampling occurs at a substantially constant phase angle within the power supply waveform.
Claim 5
Dependent Claim
142 words
An oximeter including probe means 100 having means for transmitting light of at least two different wavelengths through blood-containing tissue, sensing means 103 for transducing said transmitted light into signals, means for producing a plurality of signals corresponding to the attenuation of said transmitted light at the different wavelengths, data processing means responsive to said signals for determining the oxygen saturation Sa0 2 of blood in said tissue, and a power supply for said oximeter adapted to convert power at a power supply frequency; is characterised in that said means for producing a plurality of signals comprises means for sampling said signals at a sampling frequency and means for adjusting said sampling frequency to maintain an integer ratio between said power supply frequency and said sampling frequency such that sampling occurs at a substantially constant phase angle within the power supply waveform.
Claim 6
Dependent Claim
49 words
An oximeter as claimed in claim 3 characterised in that said means for adjusting said sampling frequency further comprises means for determining the power source frequency and means 500, 502, 504 and 506 for producing sampling control signals for controlling said sampling in dependence on said power source frequency.
Claim 7
Dependent Claim
108 words
An oximeter including means for transmitting light of at least two different wavelengths through blood-containing tissue, sensing means 103 for transducing said transmitted light of said different wavelength into signals, means producing a plurality of signals corresponding to the attenuation of said transmitted light at the different wavelengths, data processing means responsive to said signals for determining the oxygen saturation level Sa0 2 of blood in said tissue, and display means for displaying said oxygen saturation level; is characterised in that said display means further comprises a matrix display 554, said data processing means comprising means for applying signals to said matrix display for displaying a plethysmographic waveform.
Claim 8
Dependent Claim
108 words
An oximeter including means for transmitting light of at least two different wavelengths through blood-containing tissue, sensing means 103 for transducing said transmitted light of said different wavelength into signals, means producing a plurality of signals corresponding to the attenuation of said transmitted light at the different wavelengths, data processing means responsive to said signals for determining the oxygen saturation level Sa0 2 of blood in said tissue, and display means for displaying said oxygen saturation level; is characterised in that said display means further comprises a matrix display 554, said data processing means comprising means for applying signals to said matrix display for displaying a plethysmographic waveform.
Claim 9
Dependent Claim
44 words
An oximeter as claimed in claim 5, characterised in that said data processing means further comprises means for controlling said matrix display 554 also to display thereon a bar having an amplitude corresponding to the average amplitude of the AC component of said signals.
References Cited (Backward Citations)
US4407290A
Cited
US4407290B1
Cited
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