CN105572214A - Ion mobility spectrometer for simultaneously monitoring propofol and sulfur hexafluoride in expired air and application - Google Patents

Abstract

Based on ion mobility spectrometry technology, the present invention designs an ion mobility spectrometer for simultaneous monitoring of propofol and sulfur hexafluoride in exhaled air, which is used for non-invasive on-line monitoring of patients' anesthesia depth and cardiac output during surgery.

Description

Simultaneous monitoring of propofol and sulfur hexafluoride ion mobility spectrometry in exhaled breath and its application

technical field

Based on ion mobility spectrometry technology, the present invention designs an ion mobility spectrometer for simultaneous monitoring of propofol and sulfur hexafluoride in exhaled air, which is used for online monitoring of patients' anesthesia depth and cardiac output during surgery.

Background technique

Propofol is a commonly used intravenous anesthetic, which has been widely used in induction of anesthesia, maintenance of anesthesia and sedation of critically ill patients in ICU. During the operation, the concentration of propofol in the patient's blood is often closely related to the depth of anesthesia. Therefore, monitoring the concentration of propofol in the patient's body during the operation is of great significance for anesthesia monitoring. However, for the determination of propofol in blood, methods such as high performance liquid chromatography and gas chromatography-mass spectrometry are usually used; blood, as a complex biological sample, must be pretreated before its chromatographic separation, which takes a long time And it is not easy to realize online analysis. In recent years, many reports have proved that there is a close correlation between the concentration of propofol in the exhaled breath and its concentration in the blood. Information.

During the operation, if the online monitoring of the cardiac output of the anesthetized patient can be realized, it will provide an important vital sign for the patient's care and has important clinical significance. Exogenous gas rebreathing technology is a non-invasive method for measuring human cardiac output, which has the advantages of safety, simplicity and complete equipment. Exogenous gases usually contain sulfur hexafluoride, and mass spectrometry is often used for its determination. However, mass spectrometers are often large in size and expensive, so it is not easy to be popularized clinically.

Ion Mobility Spectrometry (IMS) technology is a separation and detection technology that appeared in the 1970s. Compared with traditional technologies such as mass spectrometry and chromatography, it has the characteristics of simple structure, high sensitivity, and fast analysis speed, and has been widely used. Used in explosives screening, drug inspection and online monitoring of VOCs, etc. Based on ion mobility spectrometry technology, the invention adopts a headspace sampling method to design an online monitor for propofol in blood.

Contents of the invention

The invention designs an ion mobility spectrometer for simultaneously monitoring propofol and sulfur hexafluoride in exhaled air. The core component of the ion mobility spectrometer is the ion transfer tube, which includes an ionization source, an ion gate, a migration area, a grid and an ion receiving electrode arranged coaxially in the housing; a drift gas is provided on the side wall of the housing near the ion receiving electrode The inlet, the drift gas inlet is connected with the drift gas source; the sample gas inlet is provided on the side wall of the housing between the ion gate and the ionization source; the tail gas outlet is provided on the side wall of the housing near the ionization source, and the tail gas outlet is connected to The air inlets of the air pumps are connected, and the air outlets of the air pumps are emptied.

The sulfur hexafluoride adding device is a hollow box with gas through holes on the left and right sides respectively, and the gas through holes are respectively connected with the exhaled gas source of the human body and the gas port of the anesthesia machine through gas conduits.

The sample gas inlet of the ion transfer tube is connected with the exhaled gas source of the human body and the sulfur hexafluoride adding device through the sampling tube.

The top of the tank of the sulfur hexafluoride adding device is provided with a through hole sealed by a rubber plug, and the rubber plug separates the inside of the tank from the external environment.

Operating in unidirectional airflow mode, the direction of airflow inside the ionization source is the same as that of the drift gas.

The pumping speed of the air pump is greater than the flow rate of the drift gas.

The outside of the sampling tube is heated with a heating cloth or a heating belt, and the temperature is controlled at 37-50°C.

Based on ion mobility spectrometry technology, the present invention designs an ion mobility spectrometer for simultaneous monitoring of propofol and sulfur hexafluoride in exhaled air, which is used for non-invasive on-line monitoring of patients' anesthesia depth and cardiac output during surgery.

Description of drawings

Fig. 1 is the structure schematic diagram of the on-line monitoring instrument of propofol in the blood in the present invention.

Among them, 1 is the air outlet of the air pump, 2 is the air pump, 3 is the air inlet of the air pump, 4 is the exhaust gas outlet, 5 is the ionization source, 6 is the sample gas inlet, 7 is the sampling tube, and 8 is the exhalation of the human body. Gas source, 9 is sulfur hexafluoride adding device, 10 is rubber plug, 11 is anesthesia machine, 12 is ion gate, 13 is migration area, 14 is insulating ring, 15 is conductive ring, 16 is grid, 17 is The ion receiving pole, 18 is the drift gas inlet.

Fig. 2 is the ion mobility spectrogram of simultaneous determination of sulfur hexafluoride and propofol by the present invention.

detailed description

The invention designs an ion mobility spectrometer for simultaneously monitoring propofol and sulfur hexafluoride in exhaled air. The core component of the ion mobility spectrometer is the ion transfer tube, which includes an ionization source, an ion gate, a migration area, a grid and an ion receiving electrode arranged coaxially in the housing; a drift gas is provided on the side wall of the housing near the ion receiving electrode The inlet, the drift gas inlet is connected with the drift gas source; the sample gas inlet is provided on the side wall of the housing between the ion gate and the ionization source; the tail gas outlet is provided on the side wall of the housing near the ionization source, and the tail gas outlet is connected to The air inlets of the air pumps are connected, and the air outlets of the air pumps are emptied. The ion mobility spectrometer operates in the unidirectional airflow mode, the airflow direction in the ionization source is consistent with the airflow direction of the drift gas, and the pumping speed of the air pump is greater than the flow rate of the drift gas.

The sulfur hexafluoride adding device is a hollow box with a rubber plug on the top, which separates the inside of the box from the external environment; there are gas holes on the left and right sides, and the gas holes are respectively connected to the human body through the gas conduit. The source of exhaled air is connected to the anesthesia machine. After the surgical patient is anesthetized, inject sulfur hexafluoride into the device through the rubber stopper with a syringe, and the circulation of sulfur hexafluoride in the patient's breathing circuit can be realized.

The sample gas inlet of the ion transfer tube is connected with the exhaled gas source of the human body and the sulfur hexafluoride adding device through the sampling tube; the outside of the sampling tube is heated with a heating cloth or heating belt, and the temperature is controlled at 37-50 °C. Through the action of the air pump, the patient's exhaled breath continuously enters the ion mobility spectrometer for real-time detection.

Example 1

Adopt the present invention to measure propofol and sulfur hexafluoride simultaneously, its ion migration spectrogram is as shown in Figure 2.

Claims (5)

1. monitor Propofol and sulfur hexafluoride ionic migration spectrometer in expiratory air simultaneously, it is characterized in that:

The core component of ionic migration spectrometer is transference tube, comprises the ionization source (5) of coaxial setting successively in housing, ion gate (12), migration area (13), aperture plate (16) and ion receiving pole (17); Housing sidewall near ion receiving pole is provided with drift gas entrance (18), and drift gas entrance is connected with drift gas source of the gas; Housing sidewall between ion gate and ionization source is provided with sample gas inlet (6); Sidewall near the housing of ionization source is provided with offgas outlet (4), and offgas outlet is connected with the air intake opening (3) of aspiration pump (2), gas outlet (1) emptying of aspiration pump;

Sulfur hexafluoride adding set (9) is the casing of a hollow, and the left and right sides is respectively equipped with gas via-hole, and gas via-hole is connected with Anesthesia machine (11) gas port with the expiratory air source of the gas (8) of human body respectively by gas conduit;

The sample gas inlet of transference tube is connected with sulfur hexafluoride adding set with the expiratory air source of the gas (8) of human body by sampling pipe (7).

2. sulfur hexafluoride adding set according to claim 1, is characterized in that:

The casing top of sulfur hexafluoride adding set is provided with the through hole sealed by rubber plug (10), and box house and external environment separate by rubber plug.

3. monitor an application for Propofol and sulfur hexafluoride ionic migration spectrometer in expiratory air while described in claim 1 or 2, it is characterized in that:

Run under one-way gas flow pattern, the airflow direction in ionization source is consistent with the airflow direction of drift gas.

4. application according to claim 3, is characterized in that: the pumping speed of aspiration pump is greater than the flow velocity of drift gas.

5. application according to claim 3, is characterized in that: sampling pipe outside adopts heating cloth or heating tape to heat, and temperature controls at 37 ~ 50 DEG C.