Device for determining the hemoglobin count of a patient

Abstract

The present invention relates to a device for determination of the hemoglobin amount of a patient comprising: a closed gas volume (100); a gas outlet comprising a mouth piece (47), wherein the mouth piece (47) is configured to enable inhalation and exhalation of gas into and out of the closed gas volume (100); a means for carbon monoxide supply into the closed gas volume (100); characterized in that the means for carbon monoxide supply comprises a carbon monoxide reservoir (15) which is provided with sensors for the determination of temperature (19) and pressure (17) of the carbon monoxide in the carbon monoxide reservoir (15).

Claims

1. A method for the determination of a hemoglobin amount of a patient using a carbon monoxide administration device, the carbon monoxide administration device having a closed gas volume, a gas outlet including a mouthpiece configured to enable inhalation and exhalation of gas into and out of the closed gas volume, and a carbon monoxide reservoir that provides a carbon monoxide supply into the closed gas volume, the carbon monoxide reservoir having a volume which is provided with sensors for the determination of temperature and pressure of the carbon monoxide in the carbon monoxide reservoir, wherein the method comprises the steps of: i) supplying a defined amount of carbon monoxide to the closed gas volume; ii) in and exhaling the gas in the closed gas volume by the patient; iii) non-invasively determining the amount of carbon monoxide in the blood of the patient; iv) determining the hemoglobin value based on the amount of carbon monoxide in the blood of the patient, wherein the method comprises before step i) the steps: supplying pure oxygen into the closed gas volume; and in- and exhaling of the supplied pure oxygen by the patient.

2. The method according to claim 1, comprising a step of filtering out carbon dioxide from the closed gas volume with a carbon dioxide filter arranged in the closed gas volume.

3. The method according to claim 1, comprising a step of supplying oxygen to the closed gas volume from an oxygen supply.

4. The method according to claim 3, wherein the oxygen supply includes an elastic balloon, and the method includes a step of detecting a distance between an optical means and an envelope of the elastic balloon to determine a filling volume of the elastic balloon.

5. The method according to claim 1, comprising a step of detecting the carbon monoxide content of the closed gas volume.

6. The method according to claim 1, comprising a step of determining a volume of the carbon monoxide in the carbon monoxide reservoir with a measurement inaccuracy of <10 ml.

7. The method according to claim 1, wherein the in- and exhaling of the oxygen before the step i) occurs for a first duration and the in- and exhaling of the gas in step ii) occurs for a second duration, wherein the first duration is 0.1-6 minutes.

8. The method according to claim 1, wherein the step of supplying a defined amount of carbon monoxide includes measuring the temperature and the pressure of carbon monoxide in the carbon monoxide reservoir.

Description

4. DESCRIPTION OF THE FIGURE

(1) For a better understanding of the present invention and to clarify the practical applicability a FIGURE is provided in the following and reference is made to it. It should be understood that the FIGURE represents only one example embodiment and thus it does not delimit in any manner the scope of the claimed invention.

(2) FIG. 1 shows the schematic layout of the device for the determination of the hemoglobin amount.

5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(3) In the following, the present invention is described in more detail with reference to the accompanied FIGURE which illustrates an example embodiment of the present invention. It is, however, also possible that the present invention is provided in a different manner, such that the following described embodiment is to be regarded not as limiting for the scope of the invention. The described embodiment should rather illustrate the scope of the invention to a person skilled in the art.

(4) FIG. 1 shows a schematic layout of the device for the determination of the hemoglobin amount of a patient. Herein, a CO source 1 is connected to a CO safety valve 5 via a first pressure reducer 3. The CO source 1 can be, for example, a CO gas bottle at which a large amount of CO gas is compressed with a high pressure. The connection can be for instance employed with a gas tight elastic tube, which allows that the CO source 1 can also be arranged far remote from the other parts of the device. Thus, the CO source 1 can be for instance stored in a suitable storage room, whereas the other parts of the device can be arranged in a common treatment room. The CO safety valve 5 is in turn connected to a second CO pressure reducer 7. Further, the second CO pressure reducer 7 is connected to the CO reservoir 15 via a first throttle 9 and a valve 13. The pressure is detected by a pressure sensor 11 between the first throttle 9 and the valve 13. Due to the upstream valves and throttles it can be prevented that CO gas is supplied to the subsequent system with an excessive pressure. Accordingly, damages because of an excessive pressure can be prevented at the subsequent parts of the system. Also, an undesired leakage of the toxic CO gas can be prevented.

(5) The pressure sensor 11 ensures that the CO reservoir 15 can be filled with a suitable pressure. Temperature and pressure of the CO in the CO reservoir 15 are detected by respective sensors 17, 19. If the volume of the CO reservoir 15 is known, the exact amount of supplied CO can be accordingly determined. The CO reservoir 15 is in turn connected with a second throttle 21. A CO reservoir 15 can be rinsed with CO by guiding the CO to an outlet 27 via a valve 25. Thus, the CO reservoir 15 can be brought into a defined initial state before each operation. The second throttle 21 is further connected to the closed gas volume 100 via a valve 23. Thus, a defined amount of CO can be guided into the closed gas volume 100 from the CO reservoir 15. Further, an O.sub.2 source 29 is connected to a second O.sub.2 pressure reducer 33 via a first O.sub.2 pressure reducer 31. The O.sub.2 source 29 can be for instance an O.sub.2 gas bottle at which a large amount of gas is compressed with a high pressure. As for the CO source 1 also the O.sub.2 source 29 can be connected via a gas tight tube which provides for a flexible layout of the O.sub.2 source 29. The pressure reducers 31, 33 prevent that O.sub.2 gas is supplied into the closed gas volume with excessive pressure. While the patient breathes pure O.sub.2 gas in the first time period (also denoted as rinsing with O.sub.2) the valve 35 connected with the second pressure reducer 33 is open and O.sub.2 is supplied to the closed gas volume 100. Subsequently, CO can be supplied to the closed gas volume and the valve 35 can be opened for a short time to rinse the CO which potentially remained in the supplying connections into the closed gas volume by the inflowing O.sub.2. While the patient breathes the CO enriched gas during a particular second time period, valve 35 is closed and O.sub.2 is supplied to the closed gas volume 100 via valve 37 until a desired oxygen concentration in the gas of the closed gas volume 100 is provided. The temperature of the gas in the closed gas volume 100 is detected by a temperature sensor 39. A patient in- and exhales the gas in the closed gas volume 100 with the mouth piece 47 in the direction of the arrows in the closed gas volume 100. The exhaled gas is filtered via a CO.sub.2 filter 51 which is arranged in the closed gas volume. Thus, an accumulation of CO.sub.2 gas in the closed gas volume 100 is prevented. During in- and exhalation, after supply of the CO, a first valve 43 is opened which allows for in- and exhaling into a connected elastic balloon 41. A second vale 45 of the closed gas volume 100, which connects the closed gas volume 100 with an outlet 49, is meanwhile closed. The elastic balloon 41 extends during an exhalation of the patient and contracts during an inhalation of the patient. Via the distance 57 to the envelope of the elastic balloon 41, which is determined by an optical distance detector 55, it can be determined how much gas volume remains in the elastic balloon 41. By the difference of the volumes of in- and exhalation the lung volume of the patient can also be determined. Further, the breathing frequency of the patient can be determined by the temporal volume change of the elastic balloon 41. After the patient has in- and exhaled the CO enriched gas of the closed gas volume too for a particular time, the first valve 43 of the closed gas volume too is closed and the second valve 45 is opened. Hence, the gas from the closed gas system 100 is exhaled from the patient via the outlet 49.

(6) Upstream of the second valve 45, a CO detector 53 is arranged, which can detect the CO amount of the exhaled gas. By the detection of the CO of the exhaled gas it can be determined how much CO was not taken up by the patient. This value can be used for the correction of the value of the CO amount administered to the patient. The parts of the device can be arranged in a housing 59 and the CO and O.sub.2 sources and the first pressure reducers 3, 31 can be stored outside the housing 59 and can be connected via corresponding ports with the parts inside the housing 59. This allows for a separate storage and hence for an easy exchange of the CO or O.sub.2 sources. The exhaust gases which are not needed can be guided out of the housing 59 via corresponding outlets 27, 49. Further, the balloon 41 is arranged in the housing 59 such that its distance to an optical distance detector 55, which is fixedly arranged at the housing 59, can be detected which allows for a determination of the filling volume of the elastic balloon 41. For the determination of the hemoglobin amount, a blood sample is taken from the patient before administering the CO and the concentration of the CO bound to the hemoglobin is determined. After the CO was administered to the patient and he breathed the CO enriched gas for a certain time, a blood sample is again taken from him and the concentration of the CO that is bound to the hemoglobin is determined. The concentration of CO that is bound to the hemoglobin can also be determined non-invasively for instance via optical methods. From both detections of the CO that is bound to the hemoglobin the hemoglobin amount in the blood of the patient can be subsequently determined.

LIST OF REFERENCE SIGNS

Reference Sign Part

(7) 1 CO source 3 CO pressure reducer 1 5 CO safety valve 7 CO pressure reducer 2 9 Throttle 1 11 Pressure sensor before reservoir 13 Valve before reservoir 15 CO reservoir 17 CO reservoir pressure sensor 19 CO reservoir temperature sensor 21 Throttle 2 23 Valve for CO dosage 25 Valve for CO rinsing 27 Outlet for rinsing the reservoir with CO 29 O.sub.2 source 31 O.sub.2 pressure reducer 1 33 O.sub.2 pressure reducer 2 35 Valve for O.sub.2 rinsing 37 Valve for O.sub.2 dosage 39 Temperature sensor of the gas volume 41 Elastic balloon 43 Valve 1 gas volume 45 Valve 2 gas volume 47 Mouth piece 49 Outlet of the gas volume 51 CO.sub.2 filter 53 CO detector 55 Optical distance detector 57 Distance to balloon 59 Housing 100 Closed gas volume