Abstract:
A belt connector for electrically connecting an electrode belt to a biometric device to be carried on a human or animal body. The belt connector is made from one single piece which can be economically manufactured in order to function as a single-use consumable, to be used with a matching biometric device. The connector comprises a molded plastic frame having a shaped circular or semi-circular hole with radial flexibility to function as a female snap button fastener for receiving and fastening on the front side of the frame a male snap protrusion. The belt connector further comprises fastening means for fastening to the frame a belt end of said electrode belt, and a member adjacent to said snap fastener hole to engage an electrode wire end electrically connected to said belt such that said end is in contact with said hole and comes in electrical contact with a conducting male snap fastener inserted in said hole. The belt connector and belt is configured such that a person wearing the belt under operation is insulated from current running through the belt, in order to meet existing standards for medical devices.

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure is within the field of medical devices, in particular biometric devices for measuring biosignals, and relates particularly to electrodes for such devices and in particular electrode belts and connectors for such belts. 
     BACKGROUND 
     Electrode belts are known, both for direct contact galvanic electrodes for measure cardiography signals and inductive belts used in respiratory inductive plethysmography. Prior art belts have various types of connectors, for transmitting the received signal to the respective device. There remains a need for improved belt connectors that are reliable and easy to use and maintain. 
     SUMMARY 
     The disclosure provides a belt connector for electrically connecting an electrode belt to a biometric device to be carried on a human or animal body. The belt connector is preferably made from one single piece which can be economically manufactured in order to function as a single-use consumable, to be used with a matching biometric device. The belt connector comprises a molded plastic frame having a front side and a rear side, the frame having a receiving hole, having radial flexibility to function as a female snap button fastener for receiving and fastening on the front side of the frame a male snap protrusion. The belt connector further comprises fastening means for fastening to the frame a belt end of said electrode belt, and a member adjacent to said snap fastener receiving hole to engage an electrode wire end electrically connected to said belt such that said wire end is in electrical contact with said hole, either by extending into the hole or coming in electrical contact e.g. through a bridging conductor, with a conducting male snap fastener inserted in said receiving hole. 
     The belt connector and belt should be configured such that a person wearing the belt under operation is insulated from current running through the belt, in order to meet existing standards for medical devices. The belt connector of the present disclosure is configured accordingly, and in a preferred embodiment, the belt connector comprises a shield member which is arranged on the rear side of said frame to electrically shield the wire end from the rear side exterior of the belt connector. 
     The belt connector preferably comprises a cover enclosing the connector and wire end. The cover may suitably include a pre-perforated hole overlapping the hole of the frame, or in other embodiments is made from such material that can readily be perforated by pressing the connector onto a male fastener which fits the receiving hole of the frame. 
     The belt end is fixedly engaged with the connector and the electrode wire connected to the connector such that the electrode wire is in electrical contact with the female snap fastener hole and thereby comes in electrical contact with a conducting male snap fastener inserted in the hole. 
     Preferably the belt end is engaged with the connector in a fashion allowing adjustment of the length of the belt. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIGS. 1A ,  1 B,  1 C, and  1 D illustrate a belt connector according to a first embodiment. 
         FIG. 1A  shows a prospective top view according to the first embodiment. 
         FIG. 1B  shows a prospective bottom view according to the first embodiment. 
         FIG. 1C  shows a top plan view according to the first embodiment. 
         FIG. 1D  shows a bottom plan view according to the first embodiment. 
         FIGS. 2A ,  2 B, and  2 C illustrate a belt connector and connected belt according to a second embodiment. 
         FIG. 2A  shows a prospective top view according to the second embodiment. 
         FIG. 2B  shows a prospective bottom view according to the second embodiment. 
         FIG. 2C  shows a prospective top view according to the second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The disclosed belt connector is suitable for various types of electrode belts, such as for cardiographic measurements, both in clinical settings or for training purposes, but also for belts such as RIP (respiratory inductive plethysmography) belts. 
     As mentioned above, the belt connector is intended for electrically connecting an electrode belt to a biometric device, the term biometric device in this context includes any devices for receiving electrical biosignals as well as extension cables, intermediate devices, connecting boxes, etc. or other means for receiving and transmitting the biosignals. 
     The belt connector is preferably made from any of various suitable non-conducting plastic materials, such as but not limited to ABS (acrylonitrile butadiene styrene), PC/ABS, polyethylene, e.g. low density polyethylene (LDPE) or high density polyethylene (HDPE), or derivatives such as polyethylene terephthalate (PET) or polyfluoroethylene (PTFE), or more preferably polypropylene, polyvinyl chloride, or polyamide (nylon). In other embodiments the connector is made from paper based material or other material from natural fibers. 
     The electrode belt is generally a flexible belt such as commonly used in respiratory inductance plethysmography (RIP) devices today. Such electrode belt is preferably a flexible textile belt where an electrode wire is interwoven in the belt or can be laminated between two layers, typically in a zig-zag fashion to allow longitudinal elasticity. 
     The molded frame of the connector has a front side and a rear side, which are defined as follows: the front side of the frame faces the biometric device which is fastened onto the connector for operation and the rear side faces away from the device. In the presently preferred embodiment the rear side of the connector faces the body of the patient when mounted, i.e. the belt connector comes between the patient and the biometric device. However, the biometric device can also be configured such that the device faces the patient and the belt connectors lie on top of the device, i.e. connect to the device on the face of the device facing away from the patient, thus in such embodiment the front side of the connectors face the patient and the rear side face away from the patient. 
     The frame has a receiving hole with radial flexibility to function as a female snap button fastener for receiving and fastening on the front side of the frame a male snap protrusion. A mating biometric device will thus have a corresponding mating male snap fastener which can be fastened securely onto the belt connector. The hole can preferably be shaped circular or semi-circular but may in other enbodiments have any other suitable shape, such as a general elongated shape shaped by two parallel members, suitably including guiding members to ensure proper positioning of the mating male snap member, a square opening, or the like. 
     The radial flexibility of the hole can in one embodiment be achieved by one or more slot extending from said hole. The embodiment shown if  FIGS. 1 and 2  shows two slots extending across from each other in the belt direction. The one or more slot are preferably formed by at least one elongated member having flexibility transverse to its longitudinal axis (e.g. by being sufficiently thin), thus imparting flexibility to the width of the hole. Preferably the hole is between two elongated members where one or both have sufficient and suitable flexibility to provide a snap fastener hole with suitable fastening strength. 
     As mentioned, the belt connector comprises a member adjacent to said snap fastener receiving hole to engage an electrode wire coming from the belt end. This wire must come in electrical contact with said receiving hole, either by extending into the hole or coming in electrical contact with the hole e.g. through a bridging conductor. In one embodiment, the wire end is crimped onto said member such the crimping tubing fixes the wire and conducts and connectselectrically the wire to the receiving hole, such that thus the wire and the belt is in electrical contact with a conducting male snap fastener inserted in said receiving hole. 
     The slot mentioned above can also function to provide an additional opening for a mating male projection on the biometric device. By this arrangement it is assured that the device cannot be incorrectly fastened, and the device will not fit any generic non-proprietary belts having connectors with female fasteners but without the correctly shaped and placed extended hole. 
     The connector frame has in another embodiment a separate further hole, not joined to the main fastener and electrical connection hole, where the further hole can mate with a corresponding male projection on said biometric device. Alternatively, the biometric device can have a female hole for mating with a corresponding male projection on the belt connector. 
     The connector frame further comprises fastening means for fastening to the frame a belt end of an electrode belt. The fastening means can in one embodiment comprise a slot with a row of teeth, pins or hooks, transverse to the belt direction, to engage a belt end. The slot preferably allows to insert through it a loop of the belt such that the belt length is adjusted and fixed, but preferably so that a user can later re-adjust the length. 
     In another embodiment, the fastening means comprise a ridge member, which can be a flat or sharp elongated ridge or ridge or row comprising pins or hooks, which ridge lies transverse to the belt direction and to which a belt end can be fastened onto with heat melting or gluing. Alternatively, the ridge member can have pins hooks that grab onto the belt fabric without need of heating. 
     Preferably, the frame has also an adjustment slot for user adjustment of the belt, which can configured with either of the two described fastening means, the adjustment slot having a row of teeth, pins or hooks transverse to the belt direction, through which adjustment slot a loop of said belt can be inserted, which hooks onto the teeth/pins when pulled on, such that the length of the belt can be readily adjusted but also secured in the desired adjusted length. 
     The connector will preferably include a cover substantially or essentially fully enclosing the frame, which cover either includes a pre-made hole overlapping the receiving hole of the frame, or can be readily perforated by pressing the connector onto a male fastener which fits the receiving hole of the frame. A suitable cover can be arranged by a suitably sized paper, plastic or fabric sticker (foldable sheet with glue on one side) which sticker is folded over the frame after the belt end has been fastened and the wire end electrically connected to the receiving hole, or the cover can be from but not limited to a paper envelope, a plastic envelope and a textile envelope, which envelope is suitably fastened by gluing, sewing or the like. 
     In the embodiments where the biometric device has a further male projecting member which fits within the slot of the frame or within a separate mating hole, the cover is suitably arranged with corresponding openings for such hole or slot for receiving such mating male member, and the cover may also have a suitable hole allowing the protrusion of a male protruding member being a part of the frame which fits in a mating receiving hole or slot on the mating biometric device. 
     In a preferred embodiment, the connector comprises a shield member which is arranged on the rear side of the frame to electrically shield the wire from the rear side exterior of the belt connector. The shield member is in one embodiment a sheet member extending from the frame, which sheet member is configured to be folded over onto the rear side of the frame to cover said hole and engaged wire. Such shield member molded in one piece with the frame with enough  30  strength but suitably flexible to allow folding at least once without braking allows the use of a cover enclosing the frame, which cover need not be electrically insulating, as the shield insulates the only part of the connector which could conduct electrical current of the connector, except through the hole. 
     In another aspect, the present disclosure sets forth a process for making an electrode belt with biometric belt connectors, comprising
         placing an end of a flexible electrode belt with an incorporated wire onto a belt connector as defined above, in the suitable direction in which it is to be fastened onto the connector, such that a portion of the belt end extends beyond said ridge member or row of pins,   pressing a heat element ultrasonic hot body or other means of heat transfer onto said belt and ridge member, and through the action of the heat, shearing an end piece of the belt but leaving intact the incorporated wire, thus revealing an end of said wire,
           through the action of heat from said heat element, fastening by heat melting said belt to said ridge, and   
           fastening the wire end to a member adjacent to the hole of the connector frame, such that said end is in electrical contact with said hole and comes in electrical contact with a conducting male snap fastener inserted in said hole.       

     The process further preferably comprises enclosing the connector frame with the fastened belt end and connected wire with a cover such as suitably a cover as described above. 
     DETAILED DESCRIPTION 
       FIGS. 1A ,  1 B,  1 C, and  1 D illustrate a belt connector according to a first embodiment.  FIG. 1A  shows a prospective top view according to the first embodiment. 
       FIG. 1B  shows a prospective bottom view according to the first embodiment.  FIG. 1C  shows a top plan view according to the first embodiment.  FIG. 1D  shows a bottom plan view according to the first embodiment. 
       FIGS. 2A. 2B , and  2 C illustrate a belt connector and connected belt according to a second embodiment. 
       FIG. 2A  shows a prospective top view according to the second embodiment. 
       FIG. 2B  shows a prospective bottom view according to the second embodiment. 
       FIG. 2C  shows a prospective top view according to the second embodiment. 
     As seen in the first and second embodiments of  FIGS. 1A to 1D  and  FIGS. 2A to 2C , respectively, a biometric belt connector ( 1 ) is electrically connected to an electrode belt ( 2 ). The connector ( 1 ) may comprise a molded plastic frame ( 3 ) having a front side ( 4 ) and a rear side ( 5 ), a shaped circular or semi-circular hole ( 6 ) with radial flexibility to function as a female snap button fastener, fastening means ( 7 ) which comprise a ridge member ( 12 ). According to the first embodiment, the ridge member ( 12 ) may include a series of buts which are provided transverse to the belt direction and to which the belt end can be fastened onto with heat melting or gluing. The frame ( 3 ) may include two members ( 8 ,  13 ) adjacent to said hole ( 6 ), the two members ( 8 ,  13 ) forming a slot ( 11 ) extending from the hole and a second slot ( 15 ) across from the first slot ( 11 ). 
     The elongated members and slots provide the hole with sufficient flexibility (i.e. elasticity in the width of the hole) to function as a female snap fastener. The member ( 13 ) also functions to engage an electrode wire end ( 9 ) from the belt end electrically connecting the belt with the hole and which comes in electrical contact with a conducting male snap fastener inserted in said hole. The connector further comprises a belt slot ( 14 ) with teeth members or pins ( 17 ), through which slot a loop of said belt ( 2 ) can be inserted such that it is held by the teeth/pins when pulled back, to adjust the length of the belt. 
     The connector further comprises a shield member ( 10 ) which may be molded in one piece with the frame ( 3 ) and joined to the frame with foldable hinges ( 16 ) such that the shield member can be folded over to cover the rear side of the hole and wire end.