DE1234339B - Sequence switch for a defibrillator - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

H05g

D'eutsche KL: 21g -24/01

Number: 1 234 339

File number: M 53720 VIII c / 21 g

Filing date: July 27, 1962

Opened on: February 16, 1967

The invention relates to a sequence switch for a defibrillator operating with capacitor discharges with one or more movable contact pieces, which one after the other when the switch is operated briefly brush several fixed contacts and thereby the discharge circuit of one or close several capacitors to create a series of current surges.

In a known defibrillator of this type, the sequence switch is operated by a motor. Will switched from charging to discharging by means of a push button, a The clutch engages and the sequence switch makes one turn, whereupon the clutch automatically resumes moves out. In order to suppress spark formation as much as possible, resistors are arranged in the discharge part.

It has now been shown that ventricular fibrillation can best be combated if in each case only two current impulses of opposite polarity are given in short time intervals one after the other. The two pulses should have a peak voltage of around 2500 volts and around 4 milliseconds each last, while their interval should be about 20 milliseconds. If the double impulse has not yet been successful, the treatment should be repeated after a short time (about 15 seconds). The set Values and the pulse shape must be adhered to as precisely as possible when eliminating the ventricular fibrillation a quick success should be granted. The impulses must therefore always be reproducible Wise to be delivered, and yet the device should be portable, robust and foolproof because it is often used in emergencies by inexperienced people. It should also be ready for use in the shortest possible time be independent of the power grid if necessary. These requirements include the use of a motor drive for the next switch.

The sequence switch according to the invention of the type specified above, which meets the requirements fulfilled, is characterized in that the contacts are arranged along a straight path, along which the or the contact piece (s) after triggering a locking member under the action of a Mainspring from an end position lying on one side of the contact arrangement into one on the other side of the contact arrangement lying end position moves or move.

The switch has only two rest positions, namely the unstressed end position in which the electrodes are completely disconnected from the capacitors and the voltage source, and a tensioned end position, if the contact piece counteracts the action sequence switch for a defibrillator

Applicant:

Mine Safety Appliances Company,

Pittsburgh, Pa. (V. St. A.)

Representative:

Dipl.-Ing. G. Weinhausen, patent attorney,

Munich 22, Widenmayerstr. 46

Named as inventor:

Earl Matthew Becker, Pittsburgh, Pa .;

John Joseph Bridge, Turtle Creek, Pa. (V. St. A.)

Claimed priority:

V. St. v. America June 25, 1962 (204 947)

the mainspring has been pulled out until the locking member has collapsed. In this tensioned position, too, the electrodes are separated from the voltage sources until a release device for the locking member is actuated when the two electrodes are pressed against the patient's body. The contact piece then returns at a preset speed from the tensioned to the untensioned position and, during this transition, briefly connects the charged capacitors one after the other to the electrodes, so that they are discharged through the patient's body. _;

This construction is extremely simple and reliable. The contact pieces can be freely rotated around the Be formed longitudinal axis, whereby they are in contact with the fixed contacts in new places come and so are much less exposed to contact erosion than the abrasive brushes in the known rotating switches.

Preferably, the sequence switch for generating two consecutive pulses is also included opposite current direction by means of successive discharge of two capacitors two in Axial direction one behind the other, insulated from each other contact pieces provided and four contact

709 509/374

3 4

sets available, each of two opposing through the face plate 32. The switch is cocked,

Contacts exist, which are made by the contact pieces by moving the handle 22 to the left in the drawing

can be connected to each other. The distance pulls until a locking pin 34, which is in the housing

of the individual contact sets from each other is each wall displaceable, in a circumferential groove 36 between

just as large as the distance between the front 5 see the contact pieces and they fall into the

edges of the contact pieces. So the tense position shown in broken lines is held in each case,

first and second and the third and fourth contact sets A mainspring 38 exerts a certain axial force

bridged at the same time by the contact pieces. The one on the contact pieces by means of a nylon rope 39

one contact of each contact set is with the condensate off and seeks the contact pieces to the right in the

and the other to make contact with the relaxed position on the body. The mainspring

of the patient lying electrodes connected in this way, consists in a known manner of a spiral spring, which

that two successive current pulses ent- on the one hand to a housing 40 and on the other hand to

opposite polarity occur when the contact of a shaft 41 is attached. The spring housing 40 and

Pieces from the tensioned to the untensioned position of the housing 31 are attached to the wall of a container 42

pass over. 15 attached. The mainspring 38 can be by means of a

An embodiment of the invention is now attached to the shaft 41 key 43 on the

described on the basis of the drawing. The desired tension is created here and is

F i g. 1 is a schematic circuit diagram of a device in the pulled position by ratchet wheel 44 and pawl

held with the 46 to eliminate ventricular fibrillation. The nylon rope 39 is. on one not

Sequence switch according to the invention and 20 shown drum wound within the

2 shows a longitudinal section through the sequence switch. Housing 40 is connected to the shaft 41. That

According to FIG. 1 is the power cord 1 over another end of the nylon rope that goes through the faceplate

Voltage selector switch 2 with the high voltage 33 passes through is at the end of the contact piece

generator 3 connected. The arrangement is preferably attached to the piston rod 23. A signal lamp 48,

wise made so that the device with alternating current 25 via contacts 51 and 52 in the housing with a

(220 volts) or from a battery connected to 6 or 12 volt low voltage source 49 lights up

Direct current can be fed. In the first case, when these contacts are through the contact piece 24

the power line 1 is directly bridged with the high voltage, so this is in the tensioned

voltage generator 3 connected. In case a battery is in position.

Power source is used, so is a chopper 4 30 The contact pieces are tensioned from the

or. 6 for the conversion of the direct voltage from position triggered by an electromagnet 53 a

6 or 12 volts in the AC voltage of 220 volts. Its plunger 54 turns you

interposed. The high voltage generator is angle lever 56 on the bearing pin 57, whereby

at its output a DC voltage of about the locking pin 34 on the groove 36 against a weak one

2500 volts. . 35 spring 58 is withdrawn. If necessary,

The high-voltage source 3 is connected to two parallel contacts, also triggered by means of a manually switched-off capacitors C1 and C2, which consists of an eccentric 61 rotatable on the sensor, each of which has a current limiting resistor pin 62. The Ex- Rl or R1 is connected upstream. The resistors Rl zenter can be rotated by a handle, not shown, and R2 are parallel to the same pole of the high 40. When rotating against the voltage source connected. Parallel to the counterclockwise direction in F i g. 2 he pivots the angle capacitors and the associated resistors is lever 56 such that the locking pin 34 is retracted a charge indicator consisting of the resistance. A spring 63 pulls the eccentric in its positions 7, 8 and 9 and a glow tube 11, back to the rest position.

a capacitor 12 is parallel. When the condensate 45 up the transition from the stretched into the ungesatoren Cl and Cl to their operating voltage stretched position spread the contact pieces 24 are charged, the glow discharge tube 11 begins to flash and 26 briefly a series. electrical Konken. A short-circuit switch 13 in series with a clock A, B, C and D and the diametrically opposed resistance 14 is used to discharge the contacts A ', B', C and D 'lying above the condensate. These catalysts Cl and C2. 50 contacts are just like the signal lamp contacts

The capacitors Cl and Cl are connected to the 51 and 52 in the wall of the housing 31 slide sequence switch 21 according to the invention. They have rounded ends which, a little bit in this switch, serve to push the capacitors into the axial bore 29. To discharge the contacts on the other hand and to have two short current impulses pressed inwards by leaf springs 64, which pass against theirs, which follow one another very quickly and press opposite broader ends 65, have set current directions. The switch 21 The contacts A and D are connected to one side (z. B. is designed as a piston switch and has one of the positive side) of the capacitors Cl and C 2 handle 22 at one end of an insulating rod 23, while the contacts B and C with and contact pieces 24 and 26 at the other end of the other side of these capacitors via a Dros rod. The contact pieces are separated from one another 60 seispule 66 are connected. The contacts A 'and C, and isolated and may be used in different ways are connected to the electrode El and the contacts B con-' be formed structurally. In the case shown and D ' connected to the electrode E1 . In order to make contact (see FIG. 2), they consist of metal rings 27, which reduce clock bouncing and are optionally attached to a plastic core 28. The contact contact pieces at an angle of approximately 3 ° are designed conically in the longitudinal bore 29 of a thick-walled 65, their front edges (on the right in the housing 31 made of insulating material axially from the drawing) having a smaller diameter,
sliding. The housing is through end plates 32 and the contacts A ' and C are closed with a switch 33. The piston rod 23 extends ter 51 connected in the electrode El , while the

Contacts B ' and D' are connected to a corresponding switch 51 in the electrode E 2 . The coil 53 is located in a low-voltage circuit which also contains two switches 52 in the two electrodes E1 and E 2 connected in series and is fed by a low-voltage source 67. As FIG. 1 shows, the electrodes E1 and E2 can only receive current pulses from the capacitors C1 and C 2 when, firstly, the switches 51 are closed, ... so that the electrodes with the contacts A ', B', C and D 'are connected, and second, the switches 52 are closed, whereby the sequence switch 21 is released. The electrode switches 51, 52 are closed one after the other when the contact surfaces 71 of the electrodes are pressed against the patient's body, so that these electrode surfaces are connected to the contacts of the sequence switch before this switch is triggered.

After tripping, the contact pieces of the sequence switch 21 move quickly to the right. The contact piece 26 first bridges the contacts A and A ', which are connected to the positive side of the capacitor C1 , but this does not yet close a circuit. When the contact piece 26 moves further, it comes free of the contacts A and A ' and bridges the contacts B and B', which are connected to the negative sides of the two capacitors via the choke 66 . At the same time, the contact piece 24 bridges the contacts A and A ' and thus closes a circuit which contains the capacitor C1 via the two electrodes and the patient's body (represented by the resistor X) . If the contact piece 26 bridges the contacts C and C ″, then the contact piece 24 bridges the contacts B and B ″ , whereby no current can flow since the contacts B and C are directly connected to one another. The contact pieces 24 and 26 then bridge the contacts C and C ", or D and D ', whereby capacitor C 2 is discharged in the opposite direction as capacitor C1 through the patient's body. The design of the discharge circuit and electrodes do not form part of the present invention.

The switch according to the invention has the advantage that it is a simple and reliable means of generation of electrical impulses of prescribed duration. In the embodiment described above is the transition time of the contact pieces from the tensioned to the unloaded position preferably about 20 milliseconds, with each capacitor discharge lasting about 4 milliseconds and there is a pause of about 6 milliseconds between the two discharges. These times can can of course be changed, for example by another choice of the tension of the mainspring 38 or the dimensioning of the contact pieces 24 and 26. The duration of the current pulses transmitted by the switch can be chosen to be shorter than the time required to fully discharge the capacitors will. Another advantage of the switch according to the invention is that the contact pieces to the axis of the piston rod 23 are freely rotatable, so that again and again different contact surfaces of the contact pieces come into contact with the contacts. Because of the high voltage applied, a certain spark formation on the switch contacts, so that a corresponding erosion is to be expected is. By changing the respective contact surfaces of the rotatable contact pieces, the spark load is distributed over a larger area, so that the the resulting erosion per area and time is reduced. '

Claims (7)

Claims: '" 1. Sequence switch for a defibrillator working with capacitor discharges with one or more movable contact pieces that briefly coat several fixed contacts one after the other when the switch is actuated and thereby close the discharge circuit of one or more capacitors as long as they are closed, characterized in that the contacts (A to D, A ' to D ') are arranged along a straight path (31) along which the contact piece (s) ^) (24, 26) after a locking member (34) has been triggered under the action of a mainspring (38) from one on one side of the Contact arrangement lying end position is moved or move into an end position lying on the other side of the contact arrangement. 2. Switch according to claim 1, characterized in that two contacts each when passing a contact piece can be bridged by this. 3. Switch according to claim 1 and 2, characterized by a device (43, 44) for changing the tension of the mainspring. 4. Switch according to claim 1 to 3, characterized by two with a fixed axial distance interconnected and insulated from one another contact pieces (24, 26), which in their Pass the transition from one end position to the other on several sets of contacts, with each contact set consists of two mutually opposite perpendicular to the direction of movement of the contact pieces Contacts exists and the axial distance between adjacent sets of contacts is equal to the axial distance between the leading edges of the two contact pieces and with one contact of each contact set with the high voltage source and the other contact is connected to one of the electrodes. 5. Switch according to claim 4 for generating two successive pulses with opposite one another Direction of current by means of successive discharge of two capacitors, thereby characterized in that 4 sets of contacts are provided in the switch and that the contacts such with the capacitors and the electrodes are connected that when touching the contact pieces with the first and second contact set the one capacitor with the two electrodes is connected and that when the contact pieces come into contact with the third and fourth contact sets the other capacitor, polarized opposite to that of the first capacitor before Electrodes is connected. 6. Switch according to claim 4, characterized in that the guide for the contact pieces consists of a non-conductive housing with a cylindrical bore. ■ 7. Switch according to claim 4, characterized in that the locking member (34) consists of a radial locking pin movable to the contact pieces and that there is an annular groove (36) between the contact pieces into which the Locking pin occurs when the contact pieces are in the end position in which the mainspring (38) is curious. 8. Switch according to one of the preceding claims, characterized in that the or the contact pieces are freely rotatable about their longitudinal axis. ______ Documents considered: German Auslegeschrift No. 1048 643; French additional patent specification No. 66 064 (1st addition to French patent No. 1 067 348). 1 sheet of drawings 709 509/374 2.67 Bundesdruckerei Berlin