US3848112A - Identification system - Google Patents

Abstract

An identification bracelet attached to the arm of each patient entering a hospital dispenses a plurality of magnetically coded tags having an adhesive backing for attachment to samples, prescriptions and the like to uniquely identify the source individual. Tag readers located throughout the hospital decode the magnetic tags in order to correlate an analysis with the proper patient. In the patient''s room, a portable battery operated cross-check reader compares a magnetically coded treatment tag with an identification tag from the patient''s bracelet to prevent a treatment from being given to the wrong patient.

Description

United States Patent 1191 Weichselbaum et al.

14 1 Nov. 12,1974

[ 4] IDENTIFICATION SYSTEM 3,673,389 6/l972 KflpSdmbBlIS et 61. 235/617 B [75] Inventors: Theodore E. Weichselbaum, St. OTHER PUBLICATIONS 683 33 322 wllhelmson Femon Kuntzleman et al., Automated Blood Typing, IBM Technical Bulletin, Vol. 10, No. 10, Mar. 1968. pp. [73] Assignee: Sherwood Medical Industries Inc., l,450l ,45 l.

St. Louis, Mo. 2 Filed; Sept 11 1972 Primary Examiner-Daryl W. Cook Attorney, Agent, or FirmStanley N. Garber; William [21-] App]. No.: 287,925 OMeam Related US. Application Data [62] Division ofSer. N0. 94,452,'1)66. 2, 1970. [57] ABSTRACT I An identification bracelet attached to the arm of each [52] U.S.C|. 235/6L7 R, 235/61. D patient enmring a hospital dispenses a plurality of hit. Cl 606k 5/00, 606k 7/08 g i y Coded g h g an adhesive bucking [58] F'eld of Search 235/6111 61-12 for attachment to samples, prescriptions and the like 235/61-7 61-11 61-11 C; to uniquely identify the source individual. Tag readers 5Q 149 A located throu hout the hospital decode the ma netic g g [56] References Cited tags in order to correlate an analysis with the proper UNITED STATES PATENTS patient. In the patients room, a portable battery operated cross-check reader compares a magnetically 2,939,ll /1960 Be tt tal 340/l49 A 3,009,636 11 1961 Rul n 340/149 A Coded i f tag tag fmm 3,481,195 12 1969 -Hendrickson 61111. 235 617 B w bracelet to Pi treatment from 3,513,441 5/1970 Schwend 235/6l.7 B bemg glven to the Wrong P 3,593,291 7/1971 Carter 235/6l.7 B 3,671,717 6 1972 Bieser 235/617 13 2 Clams ll Draw'ng guns CODED T465 son/ 156 WITH copcp T465 NURSES $7W77ON SERVICE CHARGE D197 1 T T 01/42 5 pom lift/6'5 WITH CODE D T9 G5 PRL'SCK/PT/ON W/Tl/ (0175.0 7455 05/1/77?! 179 4 ROCESS/N BUSINESS Uri-7C5 ADMISSION OFF/CE SHEU 1 0f 6 mwoR QwAou PATENIH,r z nv 1 21974 PATENTE NOV] 2 m4 SHEEIZOF 6 IIIIIII AIS PATENIL; z-esv 1 21974sum 5w 6 IDENTIFICATION SYSTEM This is a division, of application Ser. No. 94,452, filed Dec. 2, 1970.

This invention relates to an improved identification system particularly adapted for preventing errors in identification of individual patients in medical centers treating a large number of patients.

In most hospitals and clinical laboratories, a bracelet containing a patient identification number is permanently affixed around the arm of an incoming patient in order to identify the patient during his entire stay. Upon discharge, the bracelet is removed by severing flexible straps which affix the bracelet to the patients arm. Despite this numerous situations arise which result in errors in patient identification. When a sample is taken from a patient, the sample must be identified by the the identification (ID) number on the patients bracelet. In transferring the patients ID number, a nurse or a technician may miscopy the number, or may relay on memory or a different data source rather than actually reading the patients bracelet. In an attempt to overcome this problem, it has been proposed to attach a notched token to the patients arm, which can be read by an electromechanical reader in order to control a punch which reproduces the notched identification scheme in a card attached to a sample. Such a system is extremely costly, and not readily adapted for use in many practical situations which occur in a medical center.

An even more serious problem previously unresolved, occurs when an individual patient is to receive a treatment. Many prescription drugs and injections are identified merely by slips of paper on which the pateints name and ID number has been handwritten by a nurse or technician who is to administer the treatment. For a variety of reasons, such as the transfer of patients to differentbeds, and errors in marking the slip of paper, the wrong patient may be given a treatment. While apparatus has been proposed for correlating the results of a sample analysis with the source sample such as a blood supply container, it has not previously been suggested that such a correlation could be applied to a patient about to receive a treatment. Furthermore, the equipment used in correlating a sample analysis with a container is not readily adapted nor practical for the latter purpose.

In accordance with the present invention, an improved and unique identification system is disclosed which both initially identifies the patient, and subsequently provides a crosscheck that a particular patient is to receive a particular treatment. A patient identification bracelet of simple design is disclosed which can dispense a plurality of magnetically coded tags for attachment to samples, prescriptions and the like, to properly identify the source individual. When a patient is to receive a treatment, one tag from his bracelet is placed in a portable cross-check reader which also receives a similar tag identifying the treatment and the patient to whom the treatment is to be administered. Only when the tags are identical is a nurse or technician authorized to administer the treatment.

One object of the invention is the provision of a patient identification system in which an ID bracelet attached to a patient dispenses a plurality of magnetically coded tages which identify the patient.

Another object of this invention is the provision of a patient identification system in which a cross-check reader compares treatment identification data with patient identification data taken from the patient immediately before administration of a treatment in order to authorize the administration of the treatment.

Further advantages and features of the invention will be apparent from the following description, and from the drawings, in which:

FIG. 1 is a block diagram illustrating the identification system used in a medical center such as a hospital;

FIG. 2 is a perspective view of one embodiment of an identification braclet for dispensing a plurality of magnetically coded identificaion tags;

FIG. 3 is a cross-section of the identification bracelet, taken along lines 33 of FIG. 2;

FIG. 4 is a plan view illustrating the magnetic orientation of a tag produced by the identification bracelet,

and taken alonglines 44 of FIG. 2;

FIG. 5 is a perspective view of another embodiment of an identification bracelet for dispensing a plurality of magnetically coded identification tags;

FIG. 6 is a perspective view, partly in section, of one tag from the bracelet of FIG. 5;

FIG. 7 is a cross-section of the identification bracelet, taken along lines 77 of FIG. 5;

FIG. 8 is a diagrammatic illustration of the crosscheck reader illustrated in perspective view in FIG. 1;

FIG. 9 is a schematic diagram of the derived clock circuit used in both the cross-check reader of FIG. 8 and the tag reader of FIG. 11;

FIG. 10 is a schematic diagram of the indicator driver used in the cross-check reader of FIG. 8; and

FIG. 11 is a diagrammatic illustration of the tag reader illustrated in perspective view in FIG. 1.

While illustrative embodiments of the invention are shown in the drawings and will be described in detail herein, the invention is susceptible of embodiment in many different forms and it should be understood that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated. Throughout the specification, values and type designations will be given for certain of the components in order to disclose a complete, operative embodiment of the invention. However, it should be understood that such values and type designations are merely representative and are not critical unless specifically so stated.

Turning to FIG. 1, an identification system is illustrated for use in a hospital or other medical treatment center. A patient is first admitted in a business and admission office 20, where he or she receives anidentification bracelet 22 constructed in accordance with the present invention. Thebracelet 22 has aconventional strap 23 which is affixed around thearm 25 of the patient in order to retain the bracelet during the patients entire stay in the hospital. The patient, wearing the attached bracelet, is then transferred to one of a large number ofpatient rooms 27 for diagnosis and/or treat ment.

In accordance with the present invention, any media concerning the patient, including prescriptions, samples of the patients fluids, and the like are identified by magnetically coded carriers ortags 30 which are dispensed by thebracelet 22. For example, one magnetically codedtag 30 is attached to a prescription before it is transmitted via anurses station 32 to a pharmacy 34 where the prescription is to be filled. Thetag 30 accompanying the prescription is placed in a receptacle in atray 36 of atag reader 37, and thetray 36 is manually closed. A lever is then moved which actuates circuitry, to be described, which decodes the magnetic information on thetag 30 and produces decoded output indications, including a print-out on a paper strip orweb 39.

After the prescription is filled, a tag similar totag 30 is attached to the prescription drug bottle or container before being transmitted to thenurses station 32. The tag accompanying the treatment includes markings or handwriting which is read by a nurse in order to provide an initial determination of the patient who is to receive the treatment. The prescription drug is taken by the nurse to thepatients room 27 containing the patient who is to receive the treatment. The tag accompanying the prescription drug is then placed in a receptacle 42 in a slidingtray 44 of across-check reader 46. At this time, anew tag 30 is dispensed from thebracelet 22 and placed in another receptacle 48 in thetray 44. The tray is then manually closed and a lever is moved to activate thecross-check reader 46. If the magnetically coded tag accompanying the drug matches the magnetically coded tag from thepateints bracelet 22, aG indicator 50 is energized. This authorizes the nurse to apply the treatment to the patient. If a NO GO indicator 511 should be energized, an error is indicated, and the nurse is not authorized to administer the treatment. The cause of the error can then be traced and corrected.

In a clinical laboratory 54 which analyzes samples from patients, anothertag reader 37 is located in order to decode codedtags 30 accompanying samples. After analysis, the test results, blood type, or the like, are identified by a tag similar to that provided by the pharmacy 34. Certain data may be transmitted to thepatients room 27, and in such instances, the identification tag accompanying the analysis is compared with atag 30 taken from thebracelet 22 before posting or otherwise entering the data on a patients record. If desired, thenurses station 32, or other stations in the hospital, can also be provided withtag readers 37.

The information from the magnetically codedtags 30 is also used to supplement information which is transmittedto a centraldata processing station 60 which provides accounting information for the business office 20. Eachtag reader 37 includes keys for manually entering data concerning the operation being performed,

as analysis, drug perscription and the like, which information is automatically printed onpaper strips 39 along with the patients number from a tag being decoded. At the same time, the decoded ID number and the manually entered information produces computer coded data which is transmitted to the centerdata processing station 60 in order to update the patients personal record and his billing record.

In FIGS. 2-4, one embodiment of thepatient bracelet 22 is illustrated in detail.Bracelet 22 consists of a bottom plate 64 of flexible material such as low density polyethylene, which carries a plurality ofmagnetized areas 65 arranged to form a unique binary code for identifying one patient. By way of example, eachmagnetized area 65 may be formed by an embedded permanent magnet formed of a ferrous material, such as alnico blanks 0.030 inches in diameter, which are magnetized during manufacture with a north-south orientation transverse to the direction of movement of thetags 30 through thebracelet 22, see FIG. 4.

Bracelet 22 includes an upper section spaced from plate 64 to form a channel or slot for passage oftags 30 therethrough. Theupper section 70, formed of a flexi ble material such as low density polyethylene, similar to the material used for the lower plate 64 is permanently attached at its ends to the lower plate 64 by a pair ofrivets 72.Section 70 includes a plurality of downwardly extendingfingers 74, eachfinger 74 being located closely adjacent a different one of thepermanent magnets 65, so that as thetags 30 are drawn between thefingers 74 and the plate 64, thefingers 74 insure good contact between the tags and thepermanent magnets 65.

In order to provide an initial determination of patient identity, the patients name may be entered by any suitable means on aname card 80, and the card slid between current channel members insection 70 and over alocking tab 82, see FIG. 3, for retention within a channel. The upper, central section of the channel is open, as seen in FIG. 2, to expose the name on thename card 80. For permanent identification, the digital equivalent of the binary coding of the permanent mag nets 65 may be prestamped in alower surface 86 of the channel for the name tag.

, A plurality ofseparable tags 30 are dispensed at one time by placing a magnetizable card or form 90 into the slit opening between theteeth 74 and the lower plate 64, and manually pushing and then pulling the form 90 through the bracelet, as seen in FIG. 2. Form 90 is composed of alayer 92 of magnetizable material, as a ferrite coating, uniformly applied over one side of a flexible carrier layer 94. The opposite side of layer 94 is coated with anadhesive backing 96 for attaching individual tags, i.e., sections of the form 90, to prescriptions, sample bottles, and the like. A thin layer ofpaper 98 covers theadhesive backing 96, and can be peeled away to expose the adhesive backing when anindividual tag 30 is to be attached to an item.

For convenience, the form 90 containsperforations 100 between each separable section, so that anindividual tag 30 may be separated from the form 90. Desirably, anorientation key 102 is notched in the center of eachtag 30 to provide a reference for orienting the tag in the cross-check reader and the tag reader to be described. At the end of form 90, aspace 104 is provided for noting the patients name and number, but such identification is for purposes of convenience only, and is not used for actual identification purposes since it is subject to the same types of errors as presently occur in identification systems.Space 104 may also contain instructions for passing the form 90 through abracelet 22, and may include other means for insuring that all forms are passes through the bracelets in the same manner, as for example, by color coding the area around theorientation notches 102 and similarly'color coding one end of thebracelet 22. In addition, anedge 106 of form 90 is scalloped to prevent wrong end insertion of the form.

As the form 90 is drawn through the bracelet, theferrite coating 92 becomes magnetized in longitudinal strips extending the length of the form. These strips have a magnetic orientation corresponding to the north-south orientation of thepermanent magnets 65 embedded in the plate 64. By way of illustration, thetag 30 illustrated in FIG. 4 has been magnetized in binary coded decimal (BCD) to form the 24 bit word 0001 0010 0000 0100 0000 1000, corresponding to thedigital ID number 120408.

In FIGS. 5-7, another embodiment of thebracelet 22 is illustrated in detail. This bracelet is more economical and of simpler construction than the bracelet of FIGS. 2-4, but requires manual refilling at periodic intervals. The bracelet serves as a storage unit and dispenser of individual,precoded tags 30 which are magnetized before loading into the bracelet. Except for being precoded, eachtag 30, FIG. 6, is similar to thetag 30 in FIG. 2. Aflexible layer 1 has deposited thereon a ferrite coating, permanently magnetized during manufacture of the tag to create 24 magnetically oriented tracks. The magnetic tracks are similar to the magnetic tracks illustrated for the tag in FIG. 4, and thus thetags 30 dispensed from the bracelet in FIGS. 5-7 are magnetically compatible withtags 30 produced by the bracelet of FIGS. 2-4.

The tags are also mechanically and physically compatible, so that both type of bracelets could be used in the same hospital identification system. Similar to tag 30 in FIG. 2, thetag 30 of FIG. 6 has anadhesive layer 112 placed over themagnetized layer 110. Finally, athin paper backing 114 is placed over theadhesive layer 112 so that thelayer 114 can be peeled away and removed in order to attach thetag 30 to an item which is to be identified. Thepaper backing 114 may contain a decimal number corresponding to the binary coding of the magnetically oriented tracks inlayer 110.

As seen in FIG. 7,bracelet 22 consists of aflexible bottom plate 116, formed of low density polyethylene, and anupper plate 120, formed of similar material, and joined at its right hand end in the drawing to plate 116 by arivet 72. The space between theplates 120 and 116 defines a storage area which holds a plurality of stacked, premagnetized tags 30. A layer offoam rubber 122 serves to urge thetags 30 upward against theplate 120. A locking tab 126, attached to plate 116 by arivet 72, serves to retain the tags within the storage compartment.

In order to dispense tags,plate 120 has acentral opening 130 which exposes the topmost tag 30.= By placing a finger or thumb through theopening 130, a person can urge the topmost tag aginst and over the locking tab 126, thereby dispensing a single tab from the end of thebraclet 22. After movement of the finger or thumb urges a single tag part way out of the bracelet, the tag can be entirely removed by grasping it between the fingers and pulling.

Thebracelet 22 of FIGS. 5-7 is intended to hold a number of tags sufficient for identification purposes during a single stay of a typical patient. The bracelet is refillable by insertingtags through the same opening which is used to dispense tags. If desired, theplate 120 can be pivotally mounted to plate 116 so as to snap open for a refill operation. Although a refill operation increases the possibility of error, the procedure for refilling bracelets would desirably include several crosschecks to prevent mistake. Furthermore, it is contemplated that bracelets of different heights to hold different numbers of stacked tags may be provided, with bracelets of greater storage capacity being attached to patients expected to have a longer stay in the hospital.

In FIG. 8, thecross-check reader 46 is diagrammatically illustrated. Since the cross-check reader is both portable and self-contained, a dual power system is provided to insure long life. The system consists of a mechanical energy source which stores operator supplied energy, and an electrical energy source consisting of a pair ofbatteries 150, providing for example 4.5 volts DC. Thebatteries 150, as will appear, are switched to power the circuitry only when necessary. This switching system, in conjunction with the mechanical storage system, produces a reader of low electrical energy consumption and hence long battery life.

The I mechanical storage system consists of acoil spring 152 captured between a frame orbase 154, which mounts the mechanical and electrical devices within the housing for the reader, and aplate 156 attached to aplaten 158.Platen 158 includes a lockingnotch 160 into which alatch 162 is driven when theplaten 158 is depressed during a reset operation by manual operator motion.

Platen 158 forms a part of the slidingtray 44 which has the tag receptacles 42 and 48 located thereon. Afterindividual tags 30 are placed within the receptacles 42 and 48, the slidingdrawer 44 is closed, moving theplaten 158 downwardly to the position illustrated by dashed lines, at which position thelatch 162 is driven into thenotch 160.Latch 162 includes acoiled spring 166 trapped between ashoulder 164 and apost 168 affixed to theframe 154. In order to activate thereader 46, atrigger 170 extending through the housing for the reader is manually rotated clockwise about apivot point 172. This laterally moves a connectinglink 174 which attaches through an opening inpost 168 withlatch 162, causingspring 166 to be compressed while thelatch 162 moves out of engagement with thenotch 160.Platen 158 is then driven upward by action of thecompressed spring 152.

The speed of movement ofplaten 158 is controlled by a pneumatic damper which comprises acylinder 182 enclosing a piston connected through apiston shaft 184 withplate 156. A pair ofair vents 186 and 194 allows air trapped within thecylinder 182 to be vented to the atmosphere as thespring 152 drives theplate 156 and attachedpiston shaft 154 upward. The size of theopenings 186 and 194 are chosen to produce the desired speed of movement of theplaten 158 for the period of time that the tag receptacles 42 and 48 are being driven passed magnetic read heads 190. After passing the read heads, the piston is so located as to block theopening 186, allowing air to vent through the remainingsmaller opening 194. This causes the speed of movement of theplaten 158 to be substantially reduced, controlling the time that theindicator 50 or 51 is energized.

The movement of theplaten 158 during the operate or read mode causes the slidingtray 44 to be driven out of the housing to its intial open position, allowing the operator to remove thetags 30 in preparation for a subsequent cross-check operation. When a new reading is to be taken, another pair oftags 30 are placed in the receptacles 42 and 48, and the unit is reset by the operator closing the sliding drawer and thus moving theplaten 158 downward untillatch 162 is driven byspring 166 into thenotch 160. Any energization of the indicators is disregarded during a reset operation.

In order to read the pair of magnetically coded tags, a pair ofchannels 213 and 214 are provided for the receptacles 42 and 48, respectively. Each channel contains similar circuits, as follows. Amagnetic read head 190 has a gap located adjacent thetag 30 being read thereby. Receptacles 42 and 48 orient thetags 30 so that the magnetized tracks are located transverse to the direction of movement of theplaten 158. The first track in eachtag 30 is located at the uppermost position in FIG. 8, such that when thetrigger 170 is actuated, each of the 24 tracks is in turn driven passed its read head at the same time that the corresponding track on theopposite tag 30 is driven passed the other read head.

Eachhead 190 is connected to aread amplifier 200 of conventional construction, producing amplified pulses which are coupled to a derivedclock circuit 292, illustrated in detail in FIG. 10. The output from the derivedclock circuit 202 consists of data pulses, on aline 204, and clock pulses, on aline 205. The clock pulse cause the data to be entered into a 24bit shift register 207 of conventional construction.Shift register 207 has 24output lines 210, individually labeled 1 through 24 to correspond with the bits being stored in the corresponding shift register storage unit.

Theoutput lines 210 of the shift registers 207 in bothchannels 213 and 214 are coupled to a pair of inputs of a comparator 212. When allbits on thelines 210 from both channels match, alogic 1 bit output is provided on anoutput line 216 of comparator 212. This logic bit is coupled to anindicator driver 220, shown in detail in FIG. 11, to energize one of theindicators 50 and 51. If a 1 output indicating a match is present,GO indicator 50 is energized; and correspondingly, if a output indicating no match is present, NOGO indicator 51 is energized.

Energization of the circuit of FIG, 8 is controlled by apower cam 222 and anindicator cam 224, both affixed to platen 158. Thebattery 150 is connected between a source of reference potential orgound 226, and a positive line which leads to a pair ofswitches 230 and 232, each of the single-pole, single-throw type.Switch 230 has a movable contact 234 which closes when alink 236 abuts or engages thepower cam 222. Similarly, theswitch 232 has amovable contact 240 which closes when alink 242 engages theindicator cam 224.

Whenswitch 230 closes, power is supplied via a positivepotential line 245 to the readamplifiers 200, the deriveclock circuits 202, the shift registers 207, and the comparator 212.Power cam 222 has a width ap proximately equal to the width of the receptacles 42 and 48, and is located so link 236 engagespower cam 222 during the same period of time that the gaps in the read heads 190 are positioned adjacent thetags 30. Power is supplied toline 245 just prior to the time the first track on thetags 30 is driven past the read heads 190. Power is disconnected fromline 245 shortly after the last track on thetags 30 has passed the corresponding read heads.

Indicator cam 224 is located so that it engages link 242 after the last rack on thetags 30 has been read, but before the disconnection of power online 245. Whenswitch 240 closes, apotential line 250 energizes theindicator driver 220. Depending on the signal online 216, one of theindicators 50 or 51 is energized, and remains energized until theindicator cam 224 is driven beyond thelink 242. During thetime cam 224 is abuttinglink 242 and hence actuatingswitch 240, the piston speed is controlled by thesingal air vent 194, causing theplaten 158 to move slowly and hence energize thedriver 220 for several seconds, sufficient to allow the operator time to read th indicators.v When the piston rises further and blocks theair vent 194, further movement of theplaten 158 is terminated, and the slidingtray 44 is located at its fully open position. In this position, bothlinks 236 and 242 are located off of theircorresponding cams 222 and 224, thus denergizing the circuit.

In FIG. 9, the derivedclock circuit 202 is illustrated in detail. The signal from themagnetic read amplifier 200 is coupled through a 10kilohm resistor 260 to anoperational amplifier 262 connected to function as a DC coupled inverter. The output of the inverter is coupled through aohm resistor 264 to atrigger input 266 of a oneshot multivibrator 268, such as a type SN74121, manufactured by Texas Instruments. Adiode 270shunts input 266 toground 226 in order to clamp the input to a maximum negative potential of minus 0.6 volts.

The signal from themagnetic read amplifier 200 is also coupled through a 150ohm resistor 274 to atrigger input 276 ofa oneshot multivibrator 278 of similar type tomultivibrator 268. Adiode 280 shunts the trigger input toground 226 in order to clamp the input to a maxiumu netative potential of minus 06 volts. Each multivibrator has a 2 millisecond one shot period, determined by an RC network consisting of a 15kilohm resistor 282 and a 0.47microfarad capacitor 284, connected tomultivibrator 268, and a 15kilohm resistor 286 and a 0.47microfarad capacitor 288 connected inmultivibrator 278. The output of each multivibrator, on a line labled Q, is coupled through respective 0.l microfarad capacitors 290 and 292 to aNAND gate 294 having an output coupled to asecond NAND gate 296 to produce an output online 205 corresponding to the clock or timing pulses. Thecapacitors 290 and 292 are chosen to have values which couple rather than differentiate the outputs of the one shot multivibrators.

NAND gate 294 is normally held at alogic 1 level or high by a pair of 10kilohm resistors 300 and 301, connected between the inputs of theNAND gate 294 and the positivepotential line 245. The pair of multivibrators are cross coupled by connecting the 6 output ofmultivibrator 268 to an inhibitinput 304 ofmultivibrator 278, and by coupling the Q output ofmultivibrator 278 to an inhibitinput 306 ofmultivibrator 268. The Q output ofmultivibrator 278 corresponds toline 204 and produces the data output pulses.

Both one shotmultivibrators 268 and 278 are of the type that are only susceptable to triggering when the inhibiting input is held low (0 volts or negative). The multivibrators trigger when the trigger input thereafter goes high (positive potential), producing a high or positive going pulse on the Q output and a low or negative going pulse on the complementary 6 output.

Thespring 152 and the pneumatic damper of FIG. 8 are selected to have values which cause each channel of data on eachtag 30 to be driven past the magnetic read heads once each 200 milliseconds, when the RC networks have the previously disclosed values which produce a 2 millisecond one shot period. The operation of the FIG. 9 circuit is as follows. When a 1 bit is detected, a positive going pulse fromamplifier 200 occurs at the time the leading edge of a magnetic track passes amagnetic head 190. This pulse is coupled to bothresistors 260 and 274. The positive pulse will have no initial effect ontrigger input 266, but the pulse will triggerinput 276. Initially, it will be assumed that the output Q is high from both milivibrators, so the Q output is low to both inhibit inputs. When the positive input pulse triggers multivibrator 278 a positive pulse is put out ondata line 204. The Q output goes low causbit passes themagnetic head 190. This negative going pulse must be completely ignored by the circuit for proper decoding. When a zero bit is detected a negative pulse appears online 200 followed by a positive pulse. Likewise, this positive pulse must be ignored for proper decoding.

The c ss connection ofmultibrators 268 and 278, via the Q outputs, inhibits the opposite multivibrator during a 2 millisecond period following the first triggering of one of the multivibrators. This time period blanks out the circuit during the time that the magnetic read heads produce a signal on detecting the trailing edge of the magnetic track. Thus, the cross connection prevents false triggering by insuring that only one multivibrator is energized for each detection of a magnetic track.

If the initial input from the readamplifier 200 had been a negative going pulse, themultivibrato 268 would have been actuated. This would cause the Q output tl ereof'to go low, and the Q output to go high. The low Q output is coupled throughcapacitor 290 and produces a high output fromgate 294. This is inverted bygate 296 to produce a low going pulse onclock line 205. The absence of a simultaneous appearance of a positive pulse online 204 now indicates a zero had been read.

In FIG. 10, theindicator driver 220 is illustrated in I detail.Line 216 from the comparator is coupled through aNAND gate 310 and aresistor 312 to thegate input 314 of a three terminal switching device such as an SCI-I 316. Thegate input 314 is shunted to ground 226 through aresistor 318. TheSCR 316 controls theNO GO indicator 51. The positivepotential line 250 fromswitch 240 is coupled through a resistor 322'and a light emitting diode (LED) 324 to the anode ofSCR 316. The cathode of the SCR is directly coupled toground 226.

To control theGO indicator 50,resistor 322 is also coupled through a second light emitting diode (LED) 330 to the anode of anSCR 332 having its cathode directly coupled toground 226. Thegate input 334 forSCR 332 is coupled toground 226 through a resistor 340, and is coupled through aresistor 342 to the output of aNOT gate 344. The input ofNOT gate 344 is coupled to'the output ofNOT gate 310.

- In operation,line 216 goes positive when a match is indicated by the comparator. This produces a negative signal togate 314 and a positive signal togate 334. Whenswitch 240 is closed to indicate that valid inforrriation is present online 216,SCR 332 is triggered into conduction, thereby completing a current path to ground through theLED 330. This produces a visual GO indication, authorizing a nurse or technicain to apply a treatment to a patient. Alternatively, ifline 216 had a zero output whenswitch 240 was closed,SCR 316 would be energized, causingLED 324 to be illuminated to provide a NO GO indication. The energized LED continues to produce a visual output until the cir cuit is broken by the opening ofswitch 240.

In FIG. 11, thetag reader 37 is diagrammatically illustrated. Parts serving corresponding functions to parts in thecross-check reader 46 of FIG. 8 have been identified by the same reference numeral, and will only be briefly described in this section. The slidingtray 36 has a platen driver and a latch mechanism identical with that previously described for the slidingtray 44 of FIG. 8. Theindividual tag 30 to be read is located in areceptacle 350, only one receptacle being provided since a pair of tags are not to be compared.Platen 158 includes aprint cam 352 which actuates alinkage 354 after thetag 30 has been driven completely passed readhead 190, thereby closing aswitch 356 in order to ground an input and initiate a print cycle, as will appear. Since-thetag reader 37 is not intended to be portable, it can be located near an external source of AC power, and hence battery operation is not provided. Thereader 37 may be powered by a conventional power supply (not illustrated), connected to a conventional source of AC line voltage. Thus, the only timing provided by theplaten 158 is for automatically intitating a print cycle.

As the magnetically codedtag 30 is driven passed themagnetic read head 190, by the platen driver mechanism previously described, a series of pulses are amplitied inread amplifier 200 and coupled to the derivedclock circuit 202, illustrated in detail in FIG. 9, in order to produce data pulses online 204 and clock pulses online 205. A 24bit shift register 207 steps the data through storage units in response to the clock pulses. When all bits have been stored, the 24 output lines, collectively labeled 210, have valid information. These lines are coupled to a printerelectronics control unit 360, of known design, which controls aconventional printer mechanism 362 in order to print the data being inputted to thecontrol 360 on the paper strip orweb 39. Desirably, the printerelectronics control unit 360 includes a BCD to decimal converter, so that the data output includes the decimal equivalent of the patient ID number. The printer selected for this purpose is of the type which can simultaneously or serially print 21 spaces or characters of information across theweb 39. By way of example, the spaces may be allocated for data information of the type illustratively shown in the drawing.Control unit 360 has a number of sets of inputs corresponding to the number of items to be printed. Any conventional control for printing plural.

data can be used asunit 360, and the data can be sampled, or enteredas serial or parallel words, as desired.

A number of different types of data may be inputted to thecontrol unit 360 for printing at the same time that the patient ID number is recorded. Aservice code generator 370 includes six thumbwheel selectable switches 372, each switch having a wheel with l0 decimal digits 0 through 9. The switches 372 are of the known type which have a direct output in BCD, four lines for each switch, thus producing on a calbe 376 a 24 bit parallel word corresponding to the selected six digit service code. In operation, each station in the hospital is assigned a service code or a block of service codes. Referring to FIG. 1, the clinical laboratory 54 could be assigned decimal numbers from 100,000 to 199,999, for example. Individual numbers within this range would be assigned to services and tests performed in the Iabroatory. Number 100,001 could stand for a glucose test, number l00,002 for a CPK test, and so on. A similar procedure would apply for the pharmacy 34, which could be assigned numbers in the range 200,000 to 299,999. Commonly prescribed drugs would be assigned a range of individual numbers with individual numbers within the range indicating the dosage of the drug.

A date setunit 380 includes a plurality ofswitches 382 which provide a bit paralle word on a cable 384, which word indicates the date.

Anelectronic clock 386 can be provided, of the type which maintains the correct time after being initially set to the correct time when the unit is first turned on. This knownclock 386 has a plurality of time setbuttons 390 for resetting time after the unit has been turned off. Associated withclock 386 is adigital clock converter 392 which produces a 16 bit parallel word on acable 394, which word corresponds to the present time.

Thedata input cables 210, 376, 384 and 394, all input to thecontrol 360, which operates to actuate theprinter mechanism 362 only when a print signal is received from aNAND gate 400. One input ofgate 400 is coupled to the terminal ofswitch 356 which is closed by engagement oflinkage 354 with theprint cam 352. The other input ofgate 400 is coupled to a 24 bit clock test electronics unit 402 whose input is coupled to theclock line 205. Unit 402 may be a 24 bit counter for producing an output after counting 24 clock pulses. Only when unit 402 has an output and theswitch 356 closes is a print signal generated. Thus, unit 402 prevents a print operation should less than 24 bits be read fromtag 30, or should more than 24 bits be read, due to a malfunction.

Desirably,printer 360 has a serial digitaldata output line 404 which may be coupled to a conventional ASCII code converter 406 having an output directly coupled to thecentral data processing 60, FIG. 1. Alternatively, theconverter 406 can operate a known type of card punch, in order to produce an IBM card or the like I which contains data corresponding to the data printed onpaper web 39. Other data providing units or different combinations of units may also be utilized in thetag reader 37.

We claim:

1. In an identification system for relating items with patients, cross-check means for insuring that an identifying i'tem corresponds to an identified patient, comprising:

first identification tag means adapted to be dispensed from bracelet means attached to a single patient;

said first identification tag means carrying thereon magnetic means having a plurality of magnetic fields arranged to form a unique magnetic code for identifying a single patient;

second identification tag means adapted to be dispensed from the bracelet means and carrying thereon magnetic means having a plurality of magentic fields corresponding to the plurality of magnetic fields carried by said first identification tag means to form the unique magnetic code thereon;

means for removably attaching said second identification tag means to an item which is to be associated with said single patient;

and reader means for comparing the unique codes of said first and second identification tag means comprising plate means mounted for movement along a predetermined path between first and second positions, first and second input receptacles for rc spectively receiving said first and second identification tag means, said receptacles being disposed on said plate means for simultaneous movement therewith, first and second magnetic read heads disposed adjacent said path for respective association with said first and second input receptacles, energy storage means coupled to said plate means for storing energy in response to movement of said plate means from said first position to said second position, said plate means being movable from said second position to said first position by the energy stored in said storage means for moving said first and second identification tag means relative to said first and second read heads to produce a first series of signals corresponding to the unique magnetic code of said first identification tag means and a second series of signals corresponding to the unique magnetic code of said second identification tag means, circuitry means responsive to said first and second series of signals for producing a signal comparison, and means responsive to said signal comparison to provide a match indication when the magnetic codes of said first and second identification tag means are identical.

2. The identification system ofclaim 1 wherein said energy storage means includes spring means for normally urging said plate means toward said first position, damper means for controlling the speed of movement of said plate means from said second position to said first position, and said attaching means includes an adhesive layer on said second identification tag means.

l i= l

Claims (2)

1. In an identification system for relating items with patients, cross-check means for insuring that an identifying item corresponds to an identified patient, comprising: first identification tag means adapted to be dispensed from bracelet means attached to a single patient; said first identification tag means carrying thereon magnetic means having a plurality of magnetic fields arranged to form a unique magnetic code for identifying a single patient; second identification tag means adapted to be dispensed from the bracelet means and carrying thereon magnetic means having a plurality of magentic fields corresponding to the plurality of magnetic fields carried by said first identification tag means to form the unique magnetic code thereon; means for removably attaching said second Identification tag means to an item which is to be associated with said single patient; and reader means for comparing the unique codes of said first and second identification tag means comprising plate means mounted for movement along a predetermined path between first and second positions, first and second input receptacles for respectively receiving said first and second identification tag means, said receptacles being disposed on said plate means for simultaneous movement therewith, first and second magnetic read heads disposed adjacent said path for respective association with said first and second input receptacles, energy storage means coupled to said plate means for storing energy in response to movement of said plate means from said first position to said second position, said plate means being movable from said second position to said first position by the energy stored in said storage means for moving said first and second identification tag means relative to said first and second read heads to produce a first series of signals corresponding to the unique magnetic code of said first identification tag means and a second series of signals corresponding to the unique magnetic code of said second identification tag means, circuitry means responsive to said first and second series of signals for producing a signal comparison, and means responsieve to said signal comparison to provide a match indication when the magnetic codes of said first and second identification tag means are identical.

2. The identification system of claim 1 wherein said energy storage means includes spring means for normally urging said plate means toward said first position, damper means for controlling the speed of movement of said plate means from said second position to said first position, and said attaching means includes an adhesive layer on said second identification tag means.

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