CN102727338A - Brain fixed-point sub-hypothermia control device - Google Patents

Abstract

The invention relates to a brain fixed-point sub-low temperature control device, which includes an interventional catheter, a temperature detection element, a control system, a liquid cooling device, and a liquid pushing device. The temperature detection elements (2, 2') monitor the temperature at the inlet and outlet of the interventional catheter (1) respectively, the temperature detection element (2") monitors the temperature of the cooling liquid output by the liquid cooling device (4), and the control system (3) Send a control signal to start the liquid pushing device (5) to push the cooled liquid into the entrance of the interventional catheter at a certain rate. Using the brain fixed-point sub-low temperature control device can not only achieve accurate positioning of the brain's temperature reduction, timely and fast cooling, and maintain Mild hypothermia is accurate and reliable, and can control acute severe cerebral edema, creating conditions for promoting the recovery of brain function, thus playing an important role in reducing the mortality rate and disability rate.

Description

A brain fixed-point sub-low temperature control device

Technical field:

The invention relates to a brain fixed-point sub-low temperature control device, in particular to a local fixed-point sub-low temperature control device for timely protection of brain function in patients with cerebral hemorrhage and severe craniocerebral injury.

Background technique:

Cerebral hemorrhage and severe craniocerebral injury are diseases with high mortality and disability rates. The brain tissue of patients is damaged to varying degrees. High fever and increased vascular permeability cause cerebral edema and cerebral ischemia. If not treated in time, it will promote A vicious cycle of increased pressure.

Studies have shown that mild hypothermia (33-35°C) can prevent high fever caused by brain damage, reduce the oxygen consumption of brain cells after cerebral hemorrhage, improve the tolerance of brain cells to hypoxia, and reduce the risk of brain tissue damage. It can reduce the degree of brain tissue acidosis after brain injury, protect the blood-brain barrier, reduce and prevent the occurrence and development of cerebral edema, reduce intracranial pressure, reduce the destruction of nerve cell structure, promote the recovery of brain function, and reduce the death of nerve cells. Therefore, it can significantly reduce the damage of brain shape and function after cerebral ischemia and brain injury, and at the same time avoid the defects of deep hypothermia therapy. It also has the functions of stopping bleeding, promoting mental recovery, slowing heart rate and breathing rate, and lowering blood pressure.

Within 6-8 hours of the onset of cerebral hemorrhage and severe craniocerebral injury, mild hypothermia therapy can significantly reduce the neurological dysfunction and brain pathological damage after cerebral hemorrhage, improve the prognosis of neurological function in patients with cerebral hemorrhage, and reduce the fatality and disability rates.

Existing hypothermia treatment techniques can be divided into two types: invasive and non-invasive. Invasive cooling techniques include extracorporeal circulation cooling blood technology, intravascular cooling, rectal lavage, peritoneal lavage, etc. Non-invasive cooling techniques include ice packs , ice caps, ice blankets, alcohol wipes, etc. The former usually causes muscle tremors due to body reflexes due to the drop in body temperature, resulting in increased energy metabolism and affecting breathing and circulation; the latter has a slow cooling rate, and the low temperature state is not constant, so it is not suitable for diseases that require rapid induction of mild hypothermia.

Invention content:

The main purpose of the present invention is to design a fixed-point sub-brain that can precisely control the temperature of the local area of the brain, intervene in time, slow down the damage and apoptosis of brain cells, and promote the recovery of brain function based on the principle of the heat exchange and cooling technology in the brain blood vessels. Low temperature control device.

The instrument includes an interventional catheter, a temperature detection element, a control system, a liquid cooling device, and a liquid pushing device.

As shown in FIG. 1 , the temperature detection element 2 and the temperature detection element 2 ′ respectively monitor the temperature at the entrance and exit of the interventional catheter 1 , and transmit feedback signals to the control system 3 in real time. When the temperature detection element 2' detects that the temperature at the outlet reaches or exceeds the upper limit of the control range, the temperature range can be set between 33-35°C, and the temperature detection element 2' feeds back the signal to the control system 3, and the control system 3 sends out The control signal starts the liquid cooling device 4 to cool the liquid to the temperature control range, and the temperature detection element 2 "monitors the temperature of the cooling liquid output by the liquid cooling device 4, and feeds back the temperature signal to the control system 3, and the control system 3 sends a control signal at the same time Start the liquid pushing device 5, the liquid pushing device 5 pushes the liquid cooled by the liquid cooling device 4 into the inlet of the conduit 1 at a certain rate, and the temperature detection element 2 simultaneously monitors the temperature of the cooling liquid output by the liquid pushing device 5 and feeds it back to the control system 3 The temperature detecting element 2, the temperature detecting element 2' and the temperature detecting element 2" form feedback with the control system 3 respectively.

As shown in accompanying drawing 2, the main function of the head 6 of interventional catheter 1 is to carry out heat exchange, therefore will select the material with large thermal conductivity and non-toxic and harmless, as silver, gold etc.; The root portion 7 of interventional catheter has The two branches, respectively the inlet and the outlet, are sequentially connected to the liquid pushing device 5 and the liquid cooling device 4; the part 8 between the head 6 and the root 7 of the interventional catheter 1 is made of bio-adaptable thermal insulation material, and the middle of the catheter is useful for thermal insulation The vertical section 9 made of the material can isolate the liquid flowing in from the inlet of the conduit and the liquid flowing out of the outlet of the conduit without heat exchange.

Further improvements can be made for interventional catheters. 1 Through peripheral control circuit test experiments, catheter characteristic detection experiments, biological tissue experiments, animal and clinical experiments, temperature field data centered on the catheter head can be obtained, and two points at the entrance and exit can be established. Relationship between temperature, fluid flow rate, and catheter tip temperature field. When the selected coolant temperature is around 21°C, the faster the liquid flow rate, the shorter the time required for the center temperature of the head of the interventional catheter 1 to reach 33°C; the slower the liquid flow rate, the shorter the time required for the center temperature of the interventional catheter 1 to reach 33°C The longer it takes, but the wider the radiation range for cooling down, reaching a circular area with a radius of 2 cm.

The beneficial effect of the present invention is: within 6-8 hours of the onset of cerebral hemorrhage and severe craniocerebral injury, the brain fixed-point sub-low temperature control device can be used as soon as possible to perform sub-low temperature therapy, which can not only realize accurate positioning of brain cooling, but also reduce the temperature. It is timely and fast, maintains mild hypothermia accurately and reliably, and can control acute severe cerebral edema, creating conditions for promoting the recovery of brain function, thus playing an important role in reducing the mortality rate and disability rate. At the same time, due to the reduction of cerebral edema, the corresponding drug dosage is reduced, and the toxic and side effects of renal function damage are also correspondingly reduced, which is beneficial to prolonging the rescue time of surgery and improving the success rate of rescue. The method is reliable, easy to operate, and worthy of clinical popularization.

Description of drawings:

Accompanying drawing 1 is a block diagram of the present invention;

Accompanying drawing 2 is the schematic diagram of interventional catheter of the present invention;

Accompanying drawing 3 is the program flowchart of control system;

Accompanying drawing 4 is the interactive interface of control system;

Accompanying drawing 5 is part experimental test result.

Detailed ways:

The technical solution of the present invention will be further described below with reference to accompanying drawings 1, 2, 3, 4 and 5.

As shown in Figure 1, during treatment, an interventional catheter 1 is punctured through the femoral artery, and under the guidance of a high-definition X-ray machine, the catheter is placed in the blood vessels of the cerebral arteries, as far as possible from cerebral hemorrhage or cerebral hemorrhage. Closer parts of the injury. The cooling liquid enters the inlet of the catheter through the liquid pushing device 5, and then reaches the head of the catheter, and fully contacts the blood in the cerebral arteries for heat exchange.

The temperature detection element 2 and the temperature detection element 2 ′ can be selected from temperature sensors, which are used to monitor the temperature of the liquid at the inlet and outlet of the conduit, and feed back the signal to the control system 3 .

The control system 3 can choose C8051F021 single-chip microcomputer as the driver board, the single-chip microcomputer system is connected with the computer through the serial port, and controls the work of the peristaltic pump through the 9-bit data line. The temperature sensor is connected to the analog signal input end of the ADC, which can be strobed in turn by program control. Monitor the liquid temperature in real time according to the feedback signal of the temperature detection element, and judge when to start or stop the peristaltic pump or the cooling device according to the relationship between the temperature at the inlet and outlet of the catheter, the liquid flow rate and the temperature field of the catheter head. Push the cooled liquid into the catheter inlet at a certain rate until the temperature of the blood that exchanges heat with the catheter head reaches the target sub-low temperature.

The liquid cooling device 4 can use high-quality semiconductor refrigeration elements, and connect several pairs of thermocouples to form a commonly used thermopile. With the help of heat transfer devices, the hot end of the thermopile can dissipate heat and maintain a certain temperature. Put it in a liquid cooling device to absorb heat and generate low temperature.

The liquid cooling device 4 may also use a water circuit or an oil circuit external circulation refrigeration method to cool the liquid in the conduit to generate low temperature. Alternatively, the liquid in the conduit is cooled by a combination of the above-mentioned semiconductor refrigeration element and external circulation refrigeration.

The liquid propulsion device 5 can use a peristaltic pump with controllable flow rate, and repeatedly compress the elastic tube through the roller to make the liquid in the tube move in a certain direction. The program flow chart of the control system 3 is shown in Figure 3. The single-chip system starts to initialize and the peristaltic pump parameters are set to 30, corresponding to a maximum rate of 24ml/min. The peristaltic pump starts to work at the fastest rate, and the indicator light is on. After the core temperature reaches 33°C, the peristaltic pump will reduce the rate to a certain value, such as the rate corresponding to the rate parameter 240 is 3ml/min, so as to maintain the core temperature fluctuating between 33-34°C, and the surrounding temperature continues to move towards the center The temperature is approaching. When the central temperature is lower than 32°C, the peristaltic pump will stop working, and the above values are all measured by experiments.

Use LABVIEW to write the interactive interface of the control system 3, as shown in Figure 4, the rate of the cooling liquid can be set during initialization, that is, the infusion rate in Figure 4, and the temperature of the cooling liquid, that is, the temperature in Figure 4 1 and other parameters, the temperature field data and waveform changes of each monitoring part of the head of the interventional catheter 1 are simultaneously displayed on the interactive interface. The outer edge temperature in centimeters.

According to the experimental results, the cooling speed is firstly related to the coolant temperature. After a lot of experiments and tests, we selected the coolant temperature to be around 21°C, which can not only meet the requirements, but also reduce the discomfort to patients caused by the cooling fluid temperature being too low. As shown in Figure 5: 170 seconds after starting the cooling at a rate of 24ml/min, the central temperature of the head of interventional catheter 1 dropped to the target temperature of 33°C, while the middle temperature at a distance of 2 cm from it hardly dropped ; After 150 seconds of cooling at a rate of 12.6ml/min, the center temperature of the head of the interventional catheter 1 dropped to the target temperature of 33°C, while the middle temperature at a distance of 2cm began to decrease; at a rate of 12.6ml/min 260 seconds after starting to cool down at a rate of 6.4ml/min, the center temperature of the head of the interventional catheter 1 dropped to the target temperature of 33°C, while the middle temperature at a distance of 2cm dropped more significantly; at a rate of 3ml/min 800 seconds after the start of cooling, the central temperature of the head of the interventional catheter 1 has dropped to the target temperature of 33°C, while the middle temperature at a distance of 2cm has dropped to below 35°C, that is, when the infusion rate is 3ml/min Under this condition, the central temperature will not decrease after dropping to 33°C, while the ambient temperature can still continue to approach 33°C.

Claims (7)

1. A brain fixed-point sub-low temperature control device, comprising: an interventional catheter (1), a temperature detection element (2, 2′, 2″), a control system (3), a liquid cooling device (4), and a liquid pushing device (5), characterized in that: The interventional catheter (1) is fully in contact with the blood in the cerebral arteries and carries out heat exchange; The temperature detection elements (2, 2', 2") respectively monitor the temperature at the inlet and outlet of the interventional catheter (1) and the outlet of the liquid cooling device (4), and transmit feedback signals to the control system (3) in real time; The liquid cooling device (4) cools the liquid to a temperature preset by the control system (3); The liquid pushing device (5) pushes the liquid cooled by the liquid cooling device (4) into the entrance of the interventional catheter (1) at a certain rate; The control system (3) monitors the liquid temperature in real time according to the feedback signal of the temperature detection element (2, 2′, 2″), and starts or stops the liquid pushing device ( 5), until the temperature of the blood that is heat-exchanged with the head (6) of the interventional catheter (1) reaches the target sub-low temperature. 2. The brain fixed-point sub-low temperature control device according to claim 1, characterized in that: the head (6) of the interventional catheter (1) adopts a material with high thermal conductivity and biocompatibility; the interventional catheter ( 1) The position (8) between the head (6) and the root (7) is made of heat-insulating, biocompatible material. 3. The brain fixed-point sub-low temperature control device according to claim 2, characterized in that: the root (7) of the interventional catheter (1) has two branches, which are respectively an inlet and an outlet, which are sequentially connected to a liquid pushing device (5) and liquid cooling device (4); the vertical section (9) made of insulating material is useful in the middle of the interventional conduit (1), which can isolate the liquid flowing into the conduit inlet from the liquid flowing out of the conduit outlet. 4. The brain fixed-point sub-low temperature control device according to claim 1, characterized in that: the liquid cooling device (4) adopts semiconductor refrigeration elements, or adopts water circuit or oil circuit external circulation refrigeration, or adopts semiconductor refrigeration elements and water circuits or Combination of oil circuit external circulation refrigeration. 5. The brain fixed-point sub-low temperature control device according to claim 1, characterized in that: the liquid pushing device (5) is a peristaltic pump with controllable flow rate. 6. The brain fixed-point sub-low temperature control device according to claim 5, characterized in that: the control system (3) uses a C8051F021 single-chip microcomputer to control the liquid pushing device (5). 7. The brain fixed-point sub-low temperature control device according to any one of claims 1-6, wherein the temperature of the liquid is 21°C.

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