WO2014139535A1

WO2014139535A1 - Medical fluid injection assembly with inductive heating of the fluid

Info

Publication number: WO2014139535A1
Application number: PCT/DK2014/050054
Authority: WO
Inventors: Mikkel PRAEST; Dagny Anita JOENSEN; Carsten SOMMER
Original assignee: Syddansk Universitet
Priority date: 2013-03-11
Filing date: 2014-03-11
Publication date: 2014-09-18

Abstract

A medical fluid injection assembly comprises a syringe with an outlet and a plunger and an induction heating element disposed within the syringe, said element being suppressible by the plunger or being fitted on the plunger, in order to control the temperature on the fluid volume to be injected into a patient rather than the whole syringe. Further, an injectomate comprising said medical fluid injection assembly is disclosed.

Description

MEDICAL FLUID INJECTION ASSEMBLY WITH INDUCTIVE HEATING OF THE FLUID

FIELD OF THE INVENTION

The present invention generally relates to syringes for use with medical fluids and, more particularly, to an induction heating device for use with syringes in administrating heated medical fluids into living organisms.

BACKGROUND OF THE INVENTION

Administration of cold intravenous fluids and blood can produce substantial hypothermia, although the net effect of infusing cold solutions into the body depends on many factors such as tissue blood flow, rate of body heat generation, rate of heat loss to the outside environment, and temperature gradients within the body, age and concurrent illnesses.

A variety of commercial devices are available for warming intravenous fluids and blood. Many of these fluid warming devices do not deliver fluids at normothermia over a wide range of flows because of inefficient heat transfer of the warmer and heat loss along the length of the administrative tubing after the fluid exits the heat exchanger.

During many medical procedures, various medical fluids are injected into living organisms for purposes of diagnosis and/or treatment. Commonly, injected medical fluids include, but are not limited to IV administered medicaments, x-ray contrast media or agents, flushing solutions (e.g., isotonic saline), solutions for enteral nutrition supply, and other fluid for purposes such as enhancing diagnostics or treatment in humans. Specific examples of such medical fluids are contrast media used to enhance computed tomography, magnetic resonance imaging, and angiography. The injectomates used in these procedures are often automated devices that expel medical fluid from a syringe, through a lumen of a barrel, and into the patient. Medical fluid injectomates suitable for these applications generally include relatively large volume syringes and are capable of producing relatively large flow rates and injection pressures. The syringe and medical fluid therein may be warmed to a temperature near body temperature before the fluid is injected into a patient (e.g., into a patient's circulatory system). Heating the medical fluid prior to injection provides a benefit of reducing patient hypothermia, which may indirect reduce the relative risks of infection, coagulopathy and discomfort, etc. An additional benefit of heating the fluid prior to administration may be reduction in viscosity, which may permit the medical fluid to be injected with less effort and/or at a higher rate. A syringe having the medical fluid disposed therein may be at least temporarily stored in a heated enclosure (e.g., a warmer box) to raise or maintain a temperature of the medical fluid to the approximate body temperature of a patient. The syringe containing the medical fluid may be transferred from the warmer box to the injectomate shortly before the medical procedure (e.g., injection of the medical fluid into the patient) is scheduled to commence. After being removed from the warmer box, the syringe and medical fluid may tend to cool toward room temperature due to heat loss to the surrounding environment. The extent of the cooling may depend upon factors such as time delay before the injection commences as well as duration of the injection. In some instances, the medical fluid is not injected into the patient until several minutes after the syringe has been removed from the warmer box. This delay can allow the temperature of the medical fluid to drop (sometimes significantly) before delivering the fluid to the patient. Another concern with the cooling of the medical fluids is the cooling process that occurs in the length of the Iv Hose from the medical syringe to the patients. Several prior art devices and apparatuses are capable of warming in a localized manner a fluid to be administered or injected into a patient.

For example EP0528437 discloses an electric heater surrounding a section of the delivery line for pulsed heating the fluid at a place of the line, with the energizing duty cycle that is controlled by a monitoring unit incorporating a microprocessor and connected to temperature sensors.

EP0501179 provides for a U-shaped container in which a medical fluid flows, connected to a source of electric energy for maintaining a constant temperature of the fluid. EP0247989 provides for a disposable tubular heat exchanger that is supplied with a warming fluid.

Additional known devices provide for local heating of blood or plasma in a bag by using microwaves (EP0307895), or by means of electrically heated plates, with a portion of the delivery barrel arranged to form labyrinthine passageways and in relation of thermal exchange with the plates (EP0292076), or for the injection of sterilized fluids (FR2403082).

WO2010082826A1 discloses a syringe having an outlet and a plunger for emptying the syringe containing a medical fluid and an induction heating susceptor disposed as a part of the syringe barrel.

Another known device such as that disclosed in EP0256653 provides for a distributed heating by using a heat exchanger having an inner barrel for the blood flow and an outer barrel providing a flow path for a heating fluid.

The object of the present invention is to overcome the above mentioned limitations and shortcomings, and more particularly to provide a simple device for administering to a patient warmed liquids such as blood components, physiological and medical fluids and the like, wherein the temperature of the liquid is safely, easily and precisely controlled, without appreciably increasing the diameter of the delivery barrel, or increasing its stiffness.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided a medical fluid injection assembly, comprising:

a syringe having an outlet and a plunger for emptying the syringe containing medical fluid to be injected into a patient; and

an induction heating susceptor disposed inside the syringe, said induction heating susceptor which may be covered with a plastic materiel or in direct contact with the medical fluid of the syringe. In one preferred embodiment of the present invention the induction heating susceptor is disposed in the length direction of the syringe, preferably as a helically coiled susceptor, whereby the plunger compresses the helically coiled susceptor upon emptying the syringe from medical fluid.

In another preferred embodiment of the present invention the induction heating susceptor is disposed in the end of the syringe as a perforated susceptor disc fitting the plunger head, said heating susceptor supported by a spacer allowing passage of fluid through the heating susceptor toward the outlet of the syringe.

In still another embodiment the induction-heating susceptor is disposed as a component directly to the wall of the barrel, either with direct contact to the medical fluid or indirectly through the wall of the barrel.

In a further embodiment the induction-heating susceptor is disposed as a tubular extension at the outlet of the syringe, which may be configured to couple to a LuerLock fitting system or directly fixed/molded to the syringe. A LuerLock fitting system is described in e.g. US 5047021. The extension unit consists of a tubular wall, which may contain the induction-heated susceptor, on the inside, in the intermediate layer or the outside of the wall. If this is not the case the susceptor will be placed as an integrated central component of the extension unit, where the shape may be, but is not limited to spoked, helical or fenestrated to maximise the surface area exposed to the medical fluid.

In another aspect the present invention provides a special designed intravenous (Iv) hose to use as a temperature regulator of the heated medical fluids. Special heating electrodes placed in longitude direction or helically in the length of the Iv hose. These electrodes can continue the heating process and/or measure the current temperature of the medical fluids.

The present invention also provides a medical fluid injectomate for accommodating the medical fluid injection assembly, wherein the syringe is disposed in contact with the electronic, medical fluid injectomate, said injectomate provided with means for generating an magnetic flux so as to heat the induction heating susceptor disposed inside the syringe.

In a preferred embodiment the magnetic flux is induced by an alternate electric current having a predetermined electric power and a predetermined frequency causing the heating susceptor disposed inside the syringe to heat the medical fluid to normal physiological temperature in the range of 35-43 C.

It is preferred that the temperature of the medical fluid within the syringe of present invention is controlled through a software loop containing parameters of start temperature of the medical fluid, temperature of the surrounding environment, medical fluid flow (ml/hr) and induction effect.

The medical fluid injectomate of the present invention comprises a bracket to secure a normal as well as a specialised syringe for induction heating. In a preferred embodiment it also includes three temperature sensors, which measures the temperature of the medical fluid inside the syringe, the temperature of the surrounding environment and the temperature of the medical fluid just before it enters the patient.

In a further embodiment the medical fluid injectomate of the present invention comprises a manual or automated user interface system, which in combination with a plunger positioning system and the induction area control system are controlling the energy levels of the inductive coils. This is done to accommodate the different ways certain medical fluids need to be heated, for instance blood needs to be heated at a different way than crystalloid medical fluid.

In a preferred embodiment pertaining to syringes having the susceptor longitudinally disposed in the syringe the plunger positioning system is adopted to control the induction area in the syringe as the plunger is compressed. In this embodiment of the injectomate a sensor detects the position of the compressed plunger and henceforth only activates inductive coils in the necessary area in the syringe, thereby ensuring only the remaining medical fluid is heated, and not the whole syringe. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows the medical fluid injection assembly with the induction heating susceptor disposed in the length direction as a helically coiled susceptor, which is compressible by the plunger during emptying the syringe from medical fluid.

Figure 2 shows the medical fluid injection assembly with the induction heating susceptor disposed in the end of the syringe as a perforated susceptor disc, fitting the plunger head and the distal end of the syringe.

Figure 3 shows the medical fluid injection assembly with the induction heating susceptor disposed in the length direction integrated in the centre of the barrel with the moving parts of the specially designed plunger and the specially designed plunger head adapted to surround the susceptor creating an airtight seal.

Figure 4 shows the medical fluid injection assembly with the integrated induction- heating susceptor disposed in the length direction as an intermediate component in the barrel wall of the syringe.

Figure 5 shows the medical fluid injection assembly with the induction-heating susceptor disposed as a tubular extension at the outlet, which may be configured to couple to a LuerLock fitting system or directly fixed/moulded to the syringe.

Figure 6 shows specially designed Iv hose, which may be configured to couple to the normal, as well as the above-mentioned specialised syringe for induction heating, to the medical fluid injectomate, via a LuerLock fitting system. In this tubing the heating electrodes is disposed in the longitude or helically length of the Iv hose. Combined with a heating sensor electrode the heating process is controlled. The temperature sensor is directly connected to the interface module and sensor control loop in the medical fluid injectomate Figure 7 shows a diagram illustrating the software and interface module controlling the components of the medical fluid injectomate.

DETAILED DESCRIPTION OF THE INVENTION

In the following a number of embodiments of the present invention are described in more detail. The syringes of the present invention typically comprise a barrel having a proximal end and a distal end, and having a cavity configured chamber to hold a fluid. A plunger is disposed in the barrel and configured to advance toward the barrel distal and proximal ends. To heat the fluid of the barrel or syringe an induction heated susceptor is disposed in the syringe, said susceptor is composed of materials suitable for induction such as, but not limited to medical grade 5 titanium a and other electrically conducting metals, plastics and composite materials. The induction-heated susceptor may be located in the cavity of the barrel, thereby transmitting the received electromagnetic field, from the medical fluid injectomate in which the syringe is placed. As the shape of the induction-heated susceptor varies so much the plunger may be adapted to comply to this shape in order to fully empty the cavity of the syringe, as in case of the helically coiled susceptor, the specially designed plunger head is adapted to the shape of the compressed helically susceptor.

Referring to Figure 1 a syringe 1 of the present invention is shown with the induction heating susceptor disposed in the length direction as a helically coiled susceptor 2.

When the specially designed plunger head 3 is forced forward during emptying of the syringe 1 the helically coiled susceptor 2 is compressed thereby increasing the density of the heating area. As the plunger 4 is being compressed toward the distal end of the syringe, the situation requires a temperature regulation of the medical fluid and may be necessary through the heat control system of the injectomate (shown in Figure 7).

In one embodiment of the present invention the induction-heated susceptor is located in the distal end on the inside of the syringe. The shape of the induction-heated susceptor disc may be a round or cone shaped 6 (see Figure 2). This disc is perforated with multiple lumina 7 connecting distal and proximal end of the syringe. As the plunger is progressing, the medical fluid inside the cavity will move from the distal end to the proximal end of the susceptor disc 6. The induction process will heat the medical fluid in direct contact with the susceptor disc 6 as the plunger head 8 moves the medical fluids inside the syringe 1 outward the LuerLock system 5.

In Figure 3 the syringe is shown with the fully integrated induction heating susceptor 9 disposed in the central part of the barrel (length direction), stationary to the specially designed moving plunger 11. As the specially designed plunger and specially designed plunger head 10 is pushed forward, it moves around the stationary susceptor creating an airtight seal to fully empty the syringe containing medical fluid. In the situation of the plunger being compressed, a heating control system of the injectomate (shown in Figure 6) is necessary to control the area of the susceptor being exposed to the magnetic flux in such a way that only the area of the susceptor surrounded by medical fluid is being heated.

The induction-heated susceptor may also be located on the inner barrel wall, in the intermediate layer of the barrel wall and/or on the outer barrel wall as shown in Figure 4. The induction-heated susceptor can be fully integrated in the barrel wall 12, thereby transmitting the received electromagnetic field, from the medical fluid injectomate, into the medical fluid as energy, heating up the fluid.

In a further embodiment of the present invention the induction-heated extension unit susceptor 13 is located in a barrel/syringe extension unit 14 of the outlet, either as a fully integrated/molded part of the syringe and/or connected by a LuerLock fitting system 5, both at distal and proximal end. The distal end of the induction-heated susceptor is directly connected to a normal or specially designed IV hose 15 (Described below) via a LuerLock fitting system 5, as shown in Figure 5.

Referring to Figure 6 a further embodiment of the present invention, a specially designed intravenous (Iv) hose 15 is provided to use as a temperature regulator of the heated medical fluids.

The special designed IV hose, a temperature regulator of the heated medical fluid, is designed with a lumen to contain the heated medical fluid from the syringe, and deliver it directly into the intravenous access in the patients and a Luerlock system 5 in either ends of the Iv hose. Special heating and measure electrodes runs integrated in the longitude direction or helically in the length of the Iv hose. An anode 16 and a cathode 17 together with a heating plate 19 are used for the temperature regulation of the medical fluid. Furthermore the temperature measurement electrode 18 is integrated with the software of the injectomate.

The present invention also provides a medical fluid injectomate for the syringes of the present invention. This medical fluid injectomate, comprises of:

a bracket to secure a normal, as well as a specialised syringe for induction heating to the medical fluid injectomate.

an automated pumping system to compress the plunger of a normal as well as a specialised syringe for induction heating.

A software loop and interface to control and regulate the features of the medical fluid injectomate as shown in figure 7

a flux induction-heating device, inductor, generating a magnetic field, which induces an alternating electric current, which heats the induction susceptor in the syringe, extension unit and IV hose.

This software uses a manually programmed set point 20 of desired temperature and flow rate in which the medical fluid should be administrated, then measures data from various parameters in the sensor control loop 21 and fluid identification system 22. The fluid identification system 22 activates a differentiated protocol, which ensures the correct heating process according to which fluid is in the syringe 1 hence different medical fluids must be handled different during heating to avoid point heating (e.g. the medical fluid reached boiling temperature instant when in contact with the induction- heated susceptor) and/or damage to the cells of the medical fluid, such as haemolysis of blood components.

From this data the medical fluid heating process 23 is regulated by the induction output system 24. This software loop is continuously rechecked via the sensor control interval system 25 in pre-programmed intervals, thus ensuring a safe heating of the medical fluid. In the sensor control loop four sensor units and two control units are provided. These four sensor units measure the flow rate of the medical fluid 26, e.g. how fast the plunger is moving from the distal end to the proximal end of the syringe, the temperature of the medical fluid inside the syringe 27, the temperature of the surrounding environment 28 and the temperature of the medical fluid just before it enters the patient's circulatory system 29. The two control units, e.g. the flow rate control unit 30 and the temperature control unit 31 , check if the data from the sensor units comply with the data from the manually programmed set point 20.

If this is not the case the induction effect control unit 32 together with the induction area control unit 33 and the plunger positioning system 34 will regulate this to ensure the targeted flow rate and temperature is reached. The induction effect control unit 32 cooperates with the induction area control unit 33 to control and regulate the magnetic flux as well as the size of susceptor area is affected. This ensures the activation of only the induction coils, which affects the area of the induction-heated susceptor still in contact with/exposed to the medical fluid, e.g. not heating the whole syringe 1. The plunger positioning system 34, which is integrated with the bracket and the automated pumping system of the medical fluid injectomate, continuous identifies how compressed the plunger is.

Reference numerals:

1. Syringe

2. Helically coiled susceptor

3. Specially designed plunger head

4. Plunger

5. LuerLock fitting system

6. Perforated susceptor disc

7. Multiple lumina

8. Plunger head

9. Fully integrated susceptor

10. Susceptor plunger head

1 1. Specially designed plunger

12. Integrated susceptor

13. Extension unit susceptor

14. Extension unit

15. Specially designed IV hose

16. Anode

17. Cathode

18. Temperature measurement electrode 19. Heating plate

20. Set point for desired temperature and flow rate

21. Sensor control loop

22. Fluid identification system

23. Medical fluid heating process

24. Induction output system

25. Sensor Control Interval system

26. Flow rate sensor unit

27. Temperature sensor unit, medical fluid

28. Temperature sensor unit, surrounding environment

29. Temperature sensor unit, medical fluid near patient

30. Flow rate control unit

31. Temperature control unit

32. Induction effect control unit

33. Induction area control unit

34. Plunger positioning system

Claims

1. A medical fluid injection assembly, comprising:

an induction heating susceptor disposed inside the syringe, either attached to the inner wall surface of the syringe or as an integral part of the lumen of the syringe, said induction-heating susceptor may be covered with a plastic materiel being in direct contact with the medical fluid of the syringe.

2. The medical fluid injection assembly of claim 1 , wherein the induction-heating susceptor is disposed in the length direction of the syringe, preferably as a helically coiled susceptor, whereby the plunger compresses the coiled susceptor upon emptying the syringe from medical fluid.

3. The medical fluid injection assembly of claim 1 , wherein the induction-heating susceptor is disposed in the end of the syringe as a perforated disc or cone-shaped heating susceptor fitting the plunger head, said heating susceptor supported by a spacer allowing passage of fluid through the lumina of the heating susceptor disc toward the outlet of the syringe.

4. The medical fluid injection assembly of claim 1 , wherein the induction-heating susceptor is disposed as a component directly onto the wall of the syringe (barrel), either with direct contact to the medical fluid or indirectly through the wall of the barrel.

5. A medical fluid injectomate for accommodating the medical fluid injection assembly of any one of the claims 1-4, wherein the syringe is disposed in contact with the electronic, medical fluid injectomate, said injectomate provided with means for generating an magnetic flux so as to heat the induction heating susceptor disposed inside the syringe.

6. The medical fluid injectomate of claim 5, wherein the magnetic flux is induced by an alternate electric current having a predetermined electric power and a predetermined frequency causing the heating susceptor disposed inside the syringe to heat the medical fluid.

7. The medical fluid injectomate of claim 6, wherein the temperature of the medical fluid within the syringe of any one of the claims 1-4 is controlled through a software loop containing parameters of start temperature of the medical fluid, which medical fluid currently is in the syringe, temperature of the surrounding environment, temperature of the medical fluid just before it is injected into the patient's circulatory system, medical fluid flow, plunger positioning system and induction effect.

8. The medical fluid injection assembly of any one of the claims 1-7, wherein the induction-heating susceptor is disposed as a tubular extension at the outlet, which may be configured to couple to a LuerLock fitting system or directly fixed or molded to the syringe.

9. The medical fluid injection assembly of any one of the claims 1-8 further comprising a medical fluid IV hose for accommodating the medical fluid injection assembly, wherein the syringe may be configured to couple to the IV hose, and wherein said IV hose the induction-heated susceptor is disposed in the end nearest to the patient, just before the medical fluid enters the patient's circulatory system.

10. A medical fluid injection assembly, comprising:

a tube for transporting medical fluid from the syringe to the patient, said tube attached to the outlet of the syringe, wherein the tube has an induction heating susceptor disposed inside or outside the tube.