Pulse oximeter testing
First Claim
1. An apparatus for testing a pulse oximeter having means for optically sensing SpO2 values of living tissue, electrical drive means for electrically activating the optically sensing means, and electrical signal processing means responsive to the optically sensing means for producing an oximeter signal corresponding to the SpO2 value being sensed, said testing apparatus comprising:
- first testing means bypassing the optically sensing means and responsive to the electrical drive means for generating selected first electrical test signals respectively representative of selected SpO2 values in living tissue and for transmitting said first signals to the electrical signal processing means to test the ability of the signal processing means to process said representative SpO2 values and produce oximeter signals corresponding to the selected SpO2 values represented by the test signals generated, andsecond testing means for generating second electrical test signals, for transmitting the same to the optically sensing means, for receiving response signals from the optically sensing means in response to transmission of the second test signals, and for providing an indication of said response signals thereby to test the optically sensing means separately from said testing by the first testing means.
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Accused Products
Abstract
A method and apparatus for testing a pulse oximeter which is based on the concept of an electrical interface between the testing instrument and the oximeter rather than an optical interface. The pulse oximeter signal processor is tested separately from the probe, and still further, the optical elements, that is, the LEDs and the photodiode, of the probe are tested separately from the probe cable. With the probe disconnected from the oximeter, a modulated electrical test signal representative of SpO2 values and other parameters is generated in response to an electrical signal from the oximeter, and the test signal is applied to the oximeter signal processor, whereby the display of the oximeter shows a value of SpO2 which is compared with the SpO2 value represented by the test signal. Independently, the probe including the probe cable, the LEDs and the photodiode are respectively and separately subjected to continuity and optical sensitivity tests. Each of the main components of the oximeter is thereby separately analyzed, and the source of a defect is isolated.
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Citations
53 Claims
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1. An apparatus for testing a pulse oximeter having means for optically sensing SpO2 values of living tissue, electrical drive means for electrically activating the optically sensing means, and electrical signal processing means responsive to the optically sensing means for producing an oximeter signal corresponding to the SpO2 value being sensed, said testing apparatus comprising:
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first testing means bypassing the optically sensing means and responsive to the electrical drive means for generating selected first electrical test signals respectively representative of selected SpO2 values in living tissue and for transmitting said first signals to the electrical signal processing means to test the ability of the signal processing means to process said representative SpO2 values and produce oximeter signals corresponding to the selected SpO2 values represented by the test signals generated, and second testing means for generating second electrical test signals, for transmitting the same to the optically sensing means, for receiving response signals from the optically sensing means in response to transmission of the second test signals, and for providing an indication of said response signals thereby to test the optically sensing means separately from said testing by the first testing means. - View Dependent Claims (2, 31, 32, 33, 34, 35)
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3. An apparatus for testing a pulse oximeter capable of sensing the SpO2 in living tissue and including a probe including LEDs and a photodiode;
- and an electronic unit including an LED driver providing output signals for activating the LEDs, an electronic signal processor for receiving and processing input signals from the photodiode in response to activation of the LEDs, and a display for showing the SpO2 values represented by the input signals, said probe releasably interconnecting the LED driver and the LEDs and the photodiode and the signal processor, comprising;
means operable with the probe disconnected from the LED driver and the signal processor for providing electrical test signals in response to output signals from the LED driver; means for modulating said electrical test signals so as to provide modulated electrical test signals representative of selected SpO2 values corresponding to those in living tissue; and means for transmitting said modulated electrical test signals to the signal processor in place of said input signals to cause the signal processor to process the test signals as if they were said input signals whereby SpO2 values shown on the display can be compared with a range of selected SpO2 values corresponding to the modulated electrical test signals thereby to test said electronic unit over its normal operating range. - View Dependent Claims (4, 5, 36)
- and an electronic unit including an LED driver providing output signals for activating the LEDs, an electronic signal processor for receiving and processing input signals from the photodiode in response to activation of the LEDs, and a display for showing the SpO2 values represented by the input signals, said probe releasably interconnecting the LED driver and the LEDs and the photodiode and the signal processor, comprising;
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6. An apparatus for testing the probe of a pulse oximeter having an electronic unit including an LED driver and an electronic signal processor;
- said probe including red and IR LEDs, a photodiode, and a probe cable, said probe cable being releasably connected to the driver and the signal processor when the probe is being used to sense the SpO2 of living tissue and to feed a signal representative of the same to the signal processor, comprising;
means for supplying current to the LEDs and the photodiode while the probe is disconnected from the driver and the signal processor to provide electrical continuity outputs from the LEDs and the photodiode; means for driving the LEDs while the probe is disconnected from the driver and the signal processor so as to activate the photodiode and provide electrical sensitivity outputs from the photodiode; and means for sensing said outputs thereby to indicate the sensitivity and the continuity of the probe.
- said probe including red and IR LEDs, a photodiode, and a probe cable, said probe cable being releasably connected to the driver and the signal processor when the probe is being used to sense the SpO2 of living tissue and to feed a signal representative of the same to the signal processor, comprising;
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7. An apparatus for testing a pulse oximeter probe which includes optical sensing means providing an LED circuit including red and IR LEDs and a photodiode circuit including a photodiode, there being an interactive red LED-photodiode combination and an interactive IR LED-photodiode combination, said LED circuit, said photodiode circuit, said interactive red LED-photodiode combination, and said interactive IR LED-photodiode combination constituting first, second, third, and fourth parts, respectively, of the optical sensing means capable of being tested for continuity and sensitivity, comprising:
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current supply means simultaneously connectable to the LED and photodiode circuits for causing testing current to flow in at least one of said circuits and for producing test output signals representative of the test results on at least one of said parts of the optical sensing means; and means for receiving the test output signals and being responsive to the magnitude thereof to produce an indication of the results of said test to a user of the apparatus. - View Dependent Claims (8, 9, 10)
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11. An apparatus for testing the continuity of a pulse oximeter probe which provides an LED circuit and a photodiode circuit, said apparatus comprising:
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means for activating each of said circuits so as to produce an electrical test output in each circuit representative of whether the circuit is open, continuous or shorted; means for separating the test outputs representing the LED circuit from the test outputs representing the photodiode circuit; and means for analyzing each of said outputs to determine whether or not the LED circuit or the photodiode circuit is open, continuous or shorted. - View Dependent Claims (12, 13, 14)
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15. An apparatus for testing the sensitivity of a pulse oximeter probe which provides red and infrared LEDs an a photodiode adapted to be alternately activated by said LEDs, said apparatus comprising:
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means for electrically alternately activating the LEDs so as to produce electrical red and IR sensitivity test output signals from the photodiode; means for producing red sensitivity/IR sensitivity ratio signals from said red and IR test output signals; and means for indicating each of said red sensitivity, IR sensitivity and red sensitivity/IR sensitivity ratio signals to determine the sensitivity of the optical sensing means. - View Dependent Claims (16, 17, 44)
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18. A method for testing a pulse oximeter having means for optically sensing SpO2 values in living tissue, means for electrically activating the optically sensing means, and electrical means responsive to the optically sensing means for indicating the SpO2 value in tissue being sensed, said method comprising the steps of:
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generating first test signals representative of SpO2 values in living tissue in response to the electrically activating means and independently of the optically sensing means, transmitting the first test signals to the electrical responsive means independently of the optically sensing means to test the ability of the oximeter to indicate said representative SpO2 values, generating a second test signal independently of the electrically activating means for testing the optically sensing means, transmitting the second test signal to the optically sensing means independently of the electrically activating means, and receiving an output from the optically sensing means indicative of the responses of the optically sensing means to the second test signal, thereby to test the operability of the optically sensing means. - View Dependent Claims (19, 20, 45, 46)
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21. A method for testing a pulse oximeter over a range of values of SpO2 expected to exist in living tissue said oximeter having a probe including LEDs and a photodiode;
- and an electronic unit including an LED driver providing an output signal for activating the LEDs, an electronic signal processor for receiving and processing input signals from the photodiode representative of SpO2 values in living tissue in response to activation of the LEDs, and a display for showing the SpO2 values represented by the input signals, said probe releasably interconnecting the LED driver and the LEDs and the photodiode and the signal processor, comprising the steps of;
disconnecting the probe from the driver and signal processor; generating an electrical test signal in response to the output signal from the LED driver; modulating said electrical test signal so as to provide a modulated electrical test signals representative of selected SpO2 values in living tissue; transmitting said modulated electrical test signals to the signal processor in place of said input signals to cause the signal processor to process the test signals as if they were said input signals thereby to test said electronic unit and, displaying the selected SpO2 values so that a comparison can be made with the SpO2 values displayed by the oximeter display to determine the accuracy of the oximeter over a range of SpO2 values. - View Dependent Claims (22, 23)
- and an electronic unit including an LED driver providing an output signal for activating the LEDs, an electronic signal processor for receiving and processing input signals from the photodiode representative of SpO2 values in living tissue in response to activation of the LEDs, and a display for showing the SpO2 values represented by the input signals, said probe releasably interconnecting the LED driver and the LEDs and the photodiode and the signal processor, comprising the steps of;
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24. A method for testing a pulse oximeter probe which includes optical sensing means providing an LED circuit including red and IR LEDs and a photodiode circuit including a photodiode, there being an interactive red LED-photodiode combination and an interactive IR LED-photodiode combination, said LED circuit, said photodiode circuit, said interactive red LED-photodiode combination, and said interactive IR LED-photodiode combination constituting first, second, third, and fourth parts, respectively, of the optical sensing means one or more of which is capable of being tested for the parameters of continuity and sensitivity, comprising the steps of:
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electrically activating said circuits so as to produce electrical test output signals which are representative of at least one of the parameters to-be-tested; and sensing the test output signals and displaying an indication of whether one or more of said parts meet the standards established for said at least one of the parameters to-be-tested. - View Dependent Claims (25, 26, 27, 28, 48)
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29. A method for testing the continuity of a pulse oximeter probe which provides an LED circuit and a photodiode circuit, comprising the steps of:
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activating each of said circuits so as to produce an electrical test output in each circuit representative of whether the circuit is open, continuous or shorted; separating the test outputs representing the LED circuit from the test outputs representing the photodiode circuit; and analyzing each of said outputs to determine whether or not the LED circuit or the photodiode circuit is open, continuous or shorted. - View Dependent Claims (30)
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37. An apparatus for testing the continuity of a pulse oximeter probe which provides LED and photodiode circuits connected to LED and photodiode terminals of a probe connector, said apparatus comprising:
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means simultaneously connectable to the LED and photodiode terminals of the probe connector for activating each of said circuits so as to produce an electrical test output in each circuit representative of whether the circuit is open, continuous or shorted; and means responsive to said test outputs for displaying indicia representing whether said LED and photodiode circuits are open, continuous or shorted. - View Dependent Claims (38, 39, 40, 41, 42)
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43. An apparatus for testing the continuity of a pulse oximeter probe that has an LED circuit and a photodiode circuit, comprising
means for supplying testing current to each of the LED and photodiode circuits to produce responses including separate analog LED and photodiode continuity voltages, means for combining said voltages into a single voltage signal with alternating LED and photodiode pulses, means for converting the single voltage signal into a series of discrete digital voltage pulses representative of the alternating LED and photodiode pulses, means for sampling the digital voltage pulses, display means, and means for activating the display means with the signal samples to indicate whether the LED and photodiode circuits are open, continuous, or shorted.
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47. A method for testing a pulse oximeter probe which includes optical sensing means providing an LED circuit including red and IR LEDs and a photodiode circuit including a photodiode, there being an interactive red LED-photodiode combination and an interactive IR LED-photodiode combination said LED circuit, said photodiode circuit, said interactive red LED-photodiode combination, and said interactive IR LED-photodiode combination constituting first, second, third, and fourth parts, respectively, of the optical sensing means to be subjected to such testing including the parameters of continuity and sensitivity, comprising the steps of:
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electrically activating said circuits so as to produce electrical test output signals which are representative of the parameters to-be-tested of said parts; electrically separating the test output signals so that there is a test output signal representative of continuity for each of said first and second parts and a test output signal representative of the sensitivity for each of said third and fourth parts; and analyzing each of said output signals to determine whether or not said parts meet the standards established for said parameters.
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49. A method for testing the continuity of a pulse oximeter probe that includes an LED circuit and a photodiode circuit, comprising the steps of:
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simultaneously connecting electrical activating means to both of the LED and photodiode circuits, electrically activating each of said circuits with test signals thereby to produce an electrical test output in each circuit representative of whether the circuit is open, continuous or shorted; and processing the test outputs to provide a visual indication of whether or not each circuit is open, continuous or shorted. - View Dependent Claims (50, 51, 52)
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53. A method for testing the continuity of a pulse oximeter probe that has an LED circuit and a photodiode circuit, comprising the steps of:
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supplying current to both the LED and photodiode circuits to produce responses including separate LED and photodiode continuity voltages;
sensing said responses and combining them into a single voltage signal with alternating LED and photodiode pulses;converting the single voltage signal into a series of discrete voltage pulses representative of the alternating LED and photodiode pulses; and using the discrete voltage pulses to display indications of whether the LED and photodiode circuits are open, continuous or shorted.
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Specification