AU669172B2 - Interchangeable pneumatic connector for blood pressure monitors - Google Patents

Description

7 2 Regulatioan32

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT 99 0 4494 4~a, a e .4 09040 a C 4,44 44 44 4 9 4 4£ 44 4 0 a 4044 4444 4449 49.'

ORIGINAL

Name of Applicant: Actual Inventor: Address for service in Australia: Invention Title: CRITIKON, INC.

Thomas K. Sutton CARTER SMITH BEADLE 2 Railway Parade Camberwell Victoria 3124 Australia INTERCHANGEABLE PNEUMATIC BLOOD PRESSURE MONITORS CONNECTOR FOR The following statement is a full description of this invention, including the best method of performing it known to us la Field of the Invention The present invention relates to patient monitoring devices and, in particular, to fittings for providing interchangeable connection of such devices to the operable patient portions of the devices.

Background of the Invention oOO Many devices have been developed for the non-invasive S0 determination of blood pressure in a patient. These 0 devices comprise a bladder in the form of an attachable, 0000 adjustable cuff which is placed in a surrounding 15 relationship on a patient's limb juxtaposed an artery for 0000 providing the pressure measurement, and a microprocessing E0°0 device for reading the data generated through the cuff or 0oo bladder. The cuff or bladder is connected to the microprocessor through a tubing set and a transducer. In operation, the device inflates the cuff by supplying 0000 pressurized air through the tubing to the bladder in order to occlude the artery. Various manipulations of the air 0 pressure within the cuff are provided by adjusting the i 0pressure within the cuff and reading the response through the transducer to such reductions in the pressure. The transducer converts the pressure manipulations into electrical signals for computation by the microprocessor.

In order to appropriately measure the blood pressure in a variety of patients, different cuff sizes are provided.

These cuff sizes may range from a very small neonatal cnff to a large thigh cuff for an adult. Each of these cuffs must be attachable to a monitoring device for determining the blood pressure of the patient. Although the cuffs are CRK-177 -2 relatively universal in size and construction, the devices and the method by which they manipulate the information received through the pressurization of the cuff are different. These different devices have different set-ups for attaching the cuff to the monitoring device. These attachment devices may be a threaded, bayonet style connector or, for example, a male luer fitting at the end of a tube extending from the basic processing unit. This required maintaining an inventory of cuffs which were particularly suited for the particular monitoring device.

o 0oThus, the interchangeability of cuffs was greatly limited.

0040 Summary of the Invention It has been found desirable to have an interchangeable o 15 fitting on a blood pressure cuff such that a patient may be attached to a specific type of monitoring device, 0 00 detached from that device for transportation or for 0 0 0exchange of device and reattached to a different type of device without removing the cuff. In order to provide for 20 this, a fitting is provided at the end of the tubing which extends from the cuff. The fitting is adapted to receive a tube associated with a pneumatic device and includes a first end having a tube attachment means formed thereon 0 o and a second end which comprises an external surface defining a male thread and an internal surface defining a female taper. Advantageously, the internal surface may define a female luer fitting for receiving an associated male luer fitting from the monitoring device.

Alternatively, the second end may further include an internal cylindrical surface which receives an associated d bayonet fitting which is clamped in place by the external surface which defines the male thread.

The tube attachment means provided at the first end of the CRK-177 -3fitting may be a tapered external surface or may be a barbed formation for holding the tubing thereon.

Additionally, the surface may merely be cylindrical if sufficient interference fit is provided between the fitting and the tubing in order to maintain the connection under the pressure which will be applied to the cuff through the tubing.

Additionally, a shoulder portion of widened diameter may be provided intermediate the first and second ends in O 0 order to provide a gripping section to the fitting. This 0°09gripping section may be provided in order to assist in the o 0- threading of the connections of the second end or the o.ooo insertion of the luer fittings into the second end of the fitting.

o°0Thus provided, the fitting creates a blood pressure cuff 0 0 0 00 apparatus for use with a non-invasive blood pressure monitor which apparatus includes a bladder for inflation 0 00 °o o 20 in the cuff. A tube communicates with the bladder at a o 0 first end of the tube for inflation and deflation of the bladder, and a fitting is received at a second end of the tubing set. This fitting includes a threaded attachment o: means on an outer surface of a second end and a second attachment means for selective attachment to a blood pressure determining device.

The threaded attachment means is preferably a male thread, and the fitting may define an internal cylindrical surface which, in connection with the male threadi, receives and attaches a bayonet-type fitting. Alternatively, the second attachment xeans may be an internal tapered surface which forms a female luer fitting which receives a male luer fitting at the end of a tubing set or extending from CRK-177 4 the body of a monitoring device. The luer fitting may be spaced from the end of the fitting in order to provide the space necessary for the cylindrical surface of the associated bayonet-type fitting.

Brief Description of the Drawings Figure 1 is a perspective view of a fitting for a tubing set according to the present invention; Figure 2 is a longitudinal cross-sectional view of the fitting of Figure 1; and €ooo Figure 3 is a perspective view of a cuff tubing set with fitting.

Description of the Preferred Embodiments Referring to Figure 1, the fitting of the present o 0 invention will be described and below the operation and use of the fitting will be described in connection with oc °o 20 Figure 3. The fitting 1 has a tubing end 2 with an external surface 3. The external surface 3 has barbs 4 formed thereon for retaining a tubing set thereover. The barbs 4 are formed in a known manner at a maximum external S.diameter slightly larger than the internal diameter of the tubing set. The tubing set has the tubing end 2 of the fitting inserted therein thus deforming the tubing set radially outward in order to provide a frictional fit over the barbs 4.

The device end 5 has a surface 6 which defines a series of male threads 7. The male threads 7 are adapted to receive the female threads of a connector from a blood pressure monitoring device. This device may be of any known type and should have female threads of like pitch and depth to CRK-177 5 the male threads of the fitting. The male threads of the fitting should be chosen so as to provide a sufficient hermetic seal with the supply tubes of the device to operatively connect the fitting to the device and, therefore, operatively connect the cuff.

Referring to Figure 2, the internal construction of the fitting is easily seen. The fitting defines an internal cylindrical surface 8 at a distal end of the fitting.

This cylindrical surface 8 is sized to receive the bayonet oo .portion of the threaded connector described above. The oO° bayonet portion is received internally of the fitting while the female threaded portion of the device attachment mechanism threads on the external surface of the fitting.

15 Thus, the! combination of the threaded attachment and the receipt of the bayonet within the internal cylindrical surface 8 provides the necessary hermetic seal to the device.

S 20 The internal construction further defines an internal taper of a female luer fitting 9 which is adapted to receive a luer fitting on the device tubing set. Thus, the female luer fitting and the threaded male connection S: of the fitting end may be used in an alternative fashion.

That is, if the device to be attached to the cuff has a LI male luer fitting, it is received within the fitting and sealed to the female luer fitting 9. However, if the Sdevice has a female threaded attachment mechanism, the bayonet of the attachment mechanism is received adjacent the internal cylindrical surface 8 with the female threaded portions of the attachment mechanism being threadedly received on the outer surface of the fitting.

A passage 10 is defined by the remainder of the fitting in CRK-177 i- -6order to provide communication from one end of the fitting to the other end of the fitting. The passage and the sizing of the internal formations on the device end of the fitting are adapted to permit sufficient air flow through the fitting so as not to interfere with the operation of the monitoring device. That is, the passage must be shaped and sized so as not to provide a significant constriction to the passage of the air therethrough either during the inflate or deflate portions of the cycle.

S So° The fitting is formed out of an engineering metal or a O0:0. plastic, for example, brass and polycarbonate.

0 o0o Conveniently, the fitting may be injection molded from plastic which, once formed, is rigid with respect to the 0.r 15 tubing set. A representative fitting may have a length of approximately 0.875 inch and an internal passage diameter of 0.125 inch. The threaded end is formed with an ~oro 0: external diameter of 0.390 inch and a thread pitch of 24 threads per inch.

0. Referring now to Figure 3, the use of the device is shown.

A cuff 11 is provided with a tubing set 12 extending from the cuff and in communication with a bladder within the 0 cuff. The fitting 1 is received in interference fit at an end of the tubing set extending from the cuff. The second end of the fitting receives a threaded-type female connector 13 which extends from a tubing set attached to Sand in communication with the monitoring device. This tubing set is shown as having a free end 14 as it may be attached to any known type of pneumatic monitoring device.

Without removing the cuff 11 from a patient, the fitting 1 may be detached from the monitoring device by unthreading the connection with the tube extending to the patient monitoring device. The patient may then be CRX-177 7 transported or merely have a different device attached.

If the patient is transported, a transportable monitoring device may be used or a different monitoring device at the end of the transportation. The transport monitoring device or the second monitoring device need not have the same type of threaded fitting as is shown in Figure 3 but rather may have a luer-type fitting for attachment to the cuff. Thus, the cuff may be attached to different types of tubing sets without removing the cuff from the patient.

SooIn order to easily grip the fitting 1, a shoulder 15 is o o formed having a grip surface 16. The grip surface may be 0 0 serrated to provide better grip. The wide diameter of the O shoulder 15 increases the grip leverage and provides a oo°; 15 stop for the tubing 12 to abut.

o0"0 The invention will now be described with reference to the accompanying claims. It should be understood that the description given herein is merely representative, and the 20 scope of the invention claims should be determined with O reference to the attached claims.

CRK-177 t i 1 i

Claims (6)

1. A fitting for receiving a tube associated with a pneumatic device, said fitting adapted for attachment to any one of a variety of coupling devices and comprising: a) a first end having a tube attachment means formed thereon; b) a second end comprising: i) an external surface defining a male thread; and ii) an internal surface defining a female taper at its proximal end and a cylindrical surface at its distal end,

2. The fitting according to Claim 1 wherein said proximal internal surface defines a female luer fitting.

3. The fitting according to Claim 1 wherein said tube attachment means is an external cylindrical surface. 0 o 0 0. 4. The fitting according to C tim 1 wherein 1 tube attachment means is a 0* 15 tapered external surface, 0000 The fitting according to Claim 1 wherein said tube attachment means includes a barbed formation for holding a tube thereon.

6. The fitting according to Claim 1 furthe including a shoulder portion intermediate said first and second ends. 0O 20 7. The fitting according to Claim 6 wherein said shoulder includes an external gripping surface.

8. The fitting according to any one of the preceding claims wherein said internal S p:lg:l367.m 12 MNfah 1996 T -9- cylindrical surface is adapted to receive an associated bayonet fitting.

9. A blood pressure cuff apparatus for use with a non-invasive blood pressure monitor, said apparatus including a bladder for inflation, a tube communicating with said bladder at a first end of said tube for inflation and deflation of said bladder, and a fitting as defined in any one of the preceding claims located at a second end of said tubing for selective attachment to a blood pressure determining device. A blood pressure cuff apparatus or a fitting for receiving a tube associated with a blood pressure cuff apparatus substantially as hereinbefore described with reference to the accompanying drawings. DATED: 12 March 1996 CARTER SMITH BEADLE Patent Attorneys for the Applicant: o CRITIKON, INC. 0 0 0 o e o o ps:lg13567.res 12 March 1996 r r- ABSTRACT A fitting for a blood pressure cuff (11) providing an interchangeable pneumatic connection for attachment to different types of devices. The fitting has a first end which attaches to the cuff tubing set (12) and, for example, may have a barbed outer surface The second end is provided with a female luer fitting as well as a threaded bayonet-style connection Thus, the cuff will be attachable to either a male luer fitting on a tubing set or a female threaded, bayonet-style connection (13) on a tubing set, each coming from a device. Siit I o I