DE102009004018B4 - Device for monitoring the correct fit of a medical needle or cannula - Google Patents

Abstract

Device for checking the correct fit of a medical needle or cannula on a patient with a device for detecting moisture by soaking the absorbent pad with liquid when moisture or liquid is present and thereby pressing two electrical conductors together.

Description

The present invention relates to an apparatus for monitoring the correct seating of a medical needle on a patient having means for detecting moisture, particularly fluid, in an environment of the needle on the patient.

A dialysis machine in medical technology generally serves to control and monitor dialysis. It pumps the blood and dialysate, measures the rate of dialysis, monitors the temperature of the fluid and the correct composition of the rinse solution, detects leaks and air bubbles in the bloodstream. In dialysis, access of the fluid to a patient is generally via a catheter for insertion into body organs or a needle for puncturing vessels. Therefore, it is necessary to ensure proper access to the patient during the examination or treatment. Sometimes dialysis takes several hours, and the needle may be unintentionally pulled so that the puncture sites are exposed from the vessels, which could lead to patient bleeding if the dialysis machine does not recognize it. Therefore, it is necessary to monitor a correct seating position of the needle or cannula.

Various devices are known in the art, generally based on monitoring extracorporeal blood pressure. In practice, however, it has been shown that the sole monitoring of the pressure in the extracorporeal blood circulation slipping out, in particular the venous puncture cannula is not guaranteed with sufficient certainty.

DE 10 2006 011 313 B3 describes a device and a method with which the access to a patient, in particular the vascular access in an extracorporeal blood treatment can be monitored. The device monitors access to a patient for a device by which a fluid is delivered to or removed from the patient via a tubing. The pressure in the hose line is monitored. For example, if the diameter of the tubing changed, a kink in the tubing eventually results, which results in an increase in the pressure in the tubing which can be monitored by a pressure monitor. If the pressure exceeds a predetermined threshold, then it is concluded that the puncture cannula threatens to be withdrawn from the vessel or partially slipped out, and the limits for pre-alarms and alarms may be set.

Moreover, the above-mentioned approach also leaves something to be desired in terms of reliability. The detection of the needle pull according to the above procedure is based on a change in the pressure in the hose line. Thus, the device would not trigger an alarm if only the patch that secures the needle to the skin of the patient is pulled because the pressure in the tubing does not change in the absence of a patch. The device would also not trigger an alarm when the needle is no longer in the blood vessel, but would be plugged in somewhere else (eg in a pillow), since here too the pressure in the tubing would remain unchanged. In addition, the device can trigger a false alarm when z. B. the hose is only slightly kinked, but this does not lead to a significant disturbance of dialysis, since the pressure changes in a kinked state of the tubing.

US 2005/0038325 A1 and US 644304 B1 describe both devices with which the access to a patient, in particular the vascular access in an extracorporeal blood treatment can be monitored. They also use electrical conductors that are mounted in a bandage and have a certain distance. In the case of moisture and / or blood, the conductors are short-circuited via the moisture and / or blood and an alarm signal is generated. Due to the order of magnitude lower conductivity of blood compared to metals, these sensors respond poorly or not at all.

It is therefore an object of the present invention to provide an improved apparatus and method for checking the correct seating of a medical needle.

Preferably, the invention provides an easy-to-use, reliable, adjustable device that is compatible with existing medical devices that ensures safe monitoring of puncture access.

This object is achieved with the features according to the claims.

The present invention relates to a method and apparatus for checking the correct seating of a medical needle on a patient having means for detecting moisture, particularly fluid in an environment of the needle on the patient.

Preferably, the apparatus further comprises a dressing for placing the medical needle on the patient, wherein a detection device is connected to the dressing; and a signal device which is connected to the detection device and emits a signal when the detection device detects moisture, in particular liquid.

Preferably, the dressing is in the form of a plaster which can replace the conventional plaster in the treatment. Preferably, the signaling device further comprises a communication device which transmits the signal to further medical devices. The communication device may serve to transmit the signal to existing medical display devices and / or alarm devices via a fixed connection or wirelessly. Preferably, the device further comprises: first and second electrical conductors spaced apart from each other such that there is a first resistance therebetween and in the presence of moisture, in particular liquid, in the dressing there is a second resistance which is less than the first resistance. Preferably, the second resistance becomes significantly smaller than the first, and more preferably, it approaches or is about 0 Ω.

The device may further comprise a support which is liquid absorbent and disposed on the dressing. In the presence of moisture or liquid, the liquid-absorbent pad can absorb liquid and thereby compress the two electrical conductors.

Preferably, the first and second electrical conductors may extend through the support.

The pad can absorb the moisture and thereby squeeze the first and second electrical conductors so that the second resistor is present between the two electrical conductors.

The first resistor essentially corresponds to the resistance of an electrical insulator, and the second resistor essentially corresponds to the resistance of an electrical conductor. That is, the first electrical conductor in the unused state of the association has a distance from the second electrical conductor. As soon as liquid, for example blood and / or rinsing solution, is located between the first and the second electrical conductor, the two electrical conductors are compressed, so that an electric current can flow between them. Electricity is so low that it is not harmful to human bodies. The signaling device can trigger an alarm as soon as the current flows between the first and second electrical conductors.

Preferably, the first and second electrical conductors are connected to the signaling device and the detection device outputs a signal when there is a second resistor between the first and second electrical conductors.

Preferably, the first and the second electrical conductor are arranged in the support with each other. As an alternative, the two electrical conductors in the support can also be arranged next to one another. Preferably, the first and second electrical conductors outside the overlay of the dressing are insulated from each other with an insulating layer.

Preferably, a lower side of the dressing is adapted to provide one in contact with the skin of a patient.

Preferably, the first and second conductors are in the form of an elongated and flat metal and extend through the entire bandage on the lower side.

The present invention provides a simple construction of a venous needle-pull detector which can serve to signal the needle-pull of the venous and arterial needle from the shunt of the patient. In the case of the venous or arterial needle type detector, when the patch is detached and the needle is pulled, the machine's blood pump is stopped to prevent the patient from bleeding to death. The device of the present invention may trigger an alarm to inform the staff that the patient is suffering from blood loss.

The device, d. H. a venous needle detector, is for the dialysis machine an external alarm detector, which can be attached to the shunt arm on the shunt puncture site.

The device of the present invention can not only serve to monitor the venous or arterial needle during dialysis, but can also be used as an alarm detector for other medical device devices (eg, a catheter needle in an intensive care unit).

Advantageous embodiments of the inventions are shown by way of example in the figures. Show it:

1 a schematic plan view of the dressing according to a preferred embodiment of the present invention; and

2 a schematic side view of the dressing according to a preferred embodiment of the present invention.

An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show an exemplary embodiment of the present invention. The device has a detection device and a liquid-receptive support 2 and can serve as an alarm detector for monitoring during dialysis. The overlay or suction pad 2 is on the lower side of the bandage or plaster 1 appropriate. The two electrical conductors 3 . 4 are in the edition 2 spaced apart or side by side and extend along the lower side of the patch 1 , One end of each electrical conductor can each be connected to a connection element 5 . 6 get connected.

Furthermore, the device according to the present invention comprises a signaling device with a communication device as well as an alarm signaling cable or a wireless LAN adapter or a Bluetooth module connected to the electronic connection elements 5 . 6 . 7 and 8th be connected. The signaling device can forward a signal to other existing medical devices and / or trigger the pump stop. This alarm message can be transmitted through a cable or wirelessly (eg via wireless LAN or Bluetooth). An exemplary approach to monitoring the correct seating of the medical needle or cannula will be described below.

The patch 1 can be applied to the skin and comes through the needle or the puncture site with the absorbent pad in contact. The device of the present invention may be sterilized and packaged sterile so that it can be used for medical use. The device holds the needle in the shunt and can be attached to the arterial needle or venous needle at the puncture site. Therefore, the device is not directly on the patient's artery or vein. This is the name of the access or departure of the blood from the venous or arterial puncture site.

If the needle is pulled, ie, the correct sitting position leaves, the puncture site of the blood vessel is exposed. The edition 2 is able to absorb blood. In the absorbent pad 2 , z. B. a Saugkompresse with the metal conductors 3 and 4 there is a small airspace. The absorbent pad may also be provided of a thinly pressed sponge that quickly sucks blood or liquid and the metal conductors 3 and 4 compressed so that an electronic current can flow through them. The detection device detects the state of the needle and the communication device transmits the alarm to desired devices. An alarm or a signal can be triggered with the signaling device. The signal may be used to stop the blood pumps of the dialysis machine and / or to inform the medical staff. Consequently, bleeding of the patient can be prevented.

The bandage may be between 20 cm and 2 cm long and between 1 to 10 cm wide, preferably between 8 cm and 16 cm long and between 1 to 3 cm wide and more preferably, for example 12 cm long and 2.5 cm wide. The circulation of the association, d. H. The suction pad can be 3 cm long and 1.8 cm wide and can be provided with metal conductors. Within the Saugkompresse is a small void, in which the metal conductors are arranged at a distance of, for example, 2 to 3 mm from each other. The metal conductor may be 1 mm thin and extend to the adapter terminal or through the entire dressing. The electrically conductive pad or Pflasterzugmelder can, for example between 1 to 4 cm long and between 0.2 to 1 cm wide, preferably between 2 to 3 cm long and between 0.3 to 0.7 cm wide. However, the sizes may vary as needed.

Older dialysis machines have no alarm detectors and therefore it can happen that the blood pumps continue to run because the venous needle indicates a resistance, eg. B., when the needle hooked in the mattress of the patient bed or the like. In this case, the blood pumps are not stopped, which can lead to bleeding of the patient. In this case, the needle pull detector according to the invention can be attached to the artery or vein of the patient by sticking it to the puncture site after puncturing the shunt needles. Thus, it prevents unnecessary blood loss of the patient.

Claims (13)

Apparatus for checking the correct seating of a medical needle on a patient having means for detecting moisture by, in the presence of moisture or liquid, soaking the absorbent pad with liquid and thereby compressing two electrical conductors together. The device of claim 1, wherein the apparatus further comprises a dressing for disposing the medical needle on the patient, wherein the detection means is disposed in association, signaling means connected to the detection means and emitting a signal when the detection means is humidity or liquid detected. Device according to one of the preceding claims, wherein the signaling device further comprises a communication device which transmits the signal to another medical device. Device according to one of the preceding claims, wherein the support or the suction pad ( 2 ) on the lower side of the bandage 1 and the electrical conductors ( 3 . 4 ) in the edition ( 2 ) are arranged spaced apart from each other. Device according to any preceding claim, wherein in the absorbent "pad ( 2 ) ") With the metal conductors ( 3 . 4 ) is a small airspace. The device of claim 5, wherein the first and second conductors are connected to the signaling device, and wherein the detection device outputs a signal when there is a second resistance between the first and second conductors. Device according to one of claims 5-6, wherein the first and the second conductor are arranged in the support with each other. Device according to one of claims 5-6, wherein the first and the second conductor are arranged in the support next to each other. Apparatus according to any one of claims 5-8, wherein the first and second conductors are insulated from each other outside the overlay of the dressing with an insulating layer. The device of any of claims 2-9, wherein a lower side of the dressing is adapted to provide adhesive contact with the skin of a patient. Device according to one of claims 5-10 wherein the first and the second conductor are formed in the form of an elongated flat metal conductor. Apparatus according to any of claims 5-10, wherein the first and second conductors extend through the entire bandage on the lower side. A method of inspecting the correct seating of a medical needle on a patient comprising the step of detecting moisture and / or fluid in an environment of the patient's needle by infusing the absorbent pad with liquid and thereby providing two electrical or medical conditions Press the ladder together.

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