Total hemoglobin screening sensor
A total hemoglobin index system derives total hemoglobin (tHb) index value utilizing a depopulated emitter with an index set of LEDs. A patient fails a tHb index test if tHb measurements are trending down and/or tHb values fall below a predefined index threshold. If a patient fails the tHb index test, a high resolution sensor derives a specific tHb measurement utilizing a high resolution set of LEDs. The number of high resolution set LEDs is greater than the number of index set LEDs.
1. A system for measuring total hemoglobin in a patient comprising:
a first optical sensor configured to measure a blood parameter with a first resolution, the first optical sensor including:
a first plurality of emitters and a first detector;
a first attachment configured to dispose the first plurality of emitters and the first detector proximate a tissue site having pulsatile blood flow; and
a first sensor connector in electrical communications with the first plurality of emitters and the first detector;
a second optical sensor configured to measure the blood parameter with a second resolution, the second optical sensor including:
a second plurality of emitters and a second detector, wherein the second plurality of emitters comprises more emitters than the first plurality of emitters in the first optical sensor and the second resolution of the second optical sensor is greater than the first resolution of the first optical sensor;
a second attachment configured to dispose the second plurality of emitters and the second detector proximate the tissue site having pulsatile blood flow; and
a second sensor connector in electrical communications with the second plurality of emitters and the second detector;
a monitor configured to communicate with at least one of the first optical sensor and the second optical sensor via the first and second sensor connectors, the monitor further configured to:
measure a first total hemoglobin estimate at the first resolution using the first optical sensor; and
if the first total hemoglobin estimate is below a predetermined threshold, provide an indication to a user to attach the second optical sensor to the patient and measure a second total hemoglobin estimate at the second resolution.
2. The system according to claim 1 wherein the first plurality of emitters of the first optical sensor comprise four LEDs and the second plurality of emitters of the second optical sensor comprise eight LEDs.
3. The system according to claim 2 wherein the four LEDs of the first optical sensor are mounted on a three-lead common carrier.
4. The system according to claim 3 wherein a first one of the four LEDs is connected between a first lead and a second lead of the common carrier.
5. The system according to claim 4 wherein a second one of the four LEDs is connected between the first lead and the second lead in a polarity opposite of the first LED.
6. The system according to claim 5 wherein a third one of the four LEDs is connected between the second lead and the third lead of the common carrier.
7. The system according to claim 6 wherein the four LEDs are activated by sequentially applying a voltage between any two of the three leads.
8. The system according to claim 2 wherein the four LEDs of the first optical sensor comprise 660 nm, 905 nm, 1170 nm and 1300 nm wavelengths.
9. The system of claim 1 , wherein the monitor is further configured to generate a total hemoglobin index display comprising the first total hemoglobin estimate.
10. The system of claim 9 , wherein the total hemoglobin index display of the monitor has no time axis and further comprises a vertical bar graph for indicating a range of relative total hemoglobin values.
11. The system of claim 10 , wherein the total hemoglobin index display further comprises a pointer configured to move vertically so as to indicate a present total hemoglobin index value.
12. The system of claim 11 , wherein the total hemoglobin index display further comprises a trend indicator.
13. A method for measuring total hemoglobin in a patient, the method comprising:
attaching a first optical sensor to the patient, the first optical sensor comprising:
a first plurality of emitters and a first detector; and
a first attachment configured to dispose the first plurality of emitters and the first detector proximate a tissue site having pulsatile blood flow;
measuring a first total hemoglobin estimate at a first resolution using the first optical sensor; and
if the first total hemoglobin estimate is below a predetermined threshold, providing an indication to a user to attach a second optical sensor to the patient and measuring a second total hemoglobin estimate at a second resolution, wherein the second optical sensor comprises:
a second plurality of emitters and a second detector, wherein the second plurality of emitters comprises more emitters than the first plurality of emitters in the first optical sensor and the second resolution of the second optical sensor is greater than the first resolution of the first optical sensor;
a second attachment configured to dispose the second plurality of emitters and the second detector on the opposite portions of the tissue site having pulsatile blood flow.
14. The method according to claim 13 wherein measuring the first total hemoglobin estimate comprises sequentially transmitting 660 nm, 905 nm, 1170 nm and 1300 nm wavelengths from the first optical sensor into a fingernail portion of the tissue site.
15. The method according to claim 14 wherein receiving measuring the first total hemoglobin estimate further comprises:
detecting the wavelengths at the fingernail portion of the tissue site;
generating a sensor signal responsive to the detected wavelengths; and
transmitting the sensor signal to a monitor.
16. The method according to claim 15 further comprising:
analyzing the sensor signal to determine a total hemoglobin trend; and
graphically showing the total hemoglobin trend on a display of the monitor.
17. The method of claim 16 , wherein the display of the monitor has no time axis and comprises a vertical bar graph for indicating a range of relative total hemoglobin values.
18. The method of claim 17 , wherein the display further comprises a pointer configured to move vertically so as to indicate a present total hemoglobin index value.
19. The method of claim 18 , wherein the display further comprises a trend indicator.
20. The method according to claim 13 , wherein the first plurality of emitters comprises four LEDs and the second plurality of emitters comprises eight LEDs.