Abstract:
This invention relates to a unitary hand held medical prescription transcriber and printing unit. More specifically, a small, portable electronic device is provided which can record words spoken by a physician and from those words generate a printed medical prescription that is delivered directly from the device itself. The unit digitizes words spoken by the user, processes the speech to recognize the words spoken by comparing the acoustic spectral characteristics of the spoken words to the characteristics of a database of known words, formats those words in the form of a prescription, and prints the prescription onto paper using a small integral printer contained in the unit. In a alternate embodiment, the unit may display the prescription on a liquid crystal display screen and the user may edit the prescription before printing a hard copy. The unit assists in accurate dispensing of medicines by providing a legible prescription printout, while at the same time being neither time consuming nor difficult to operate.

Description:
FIELD OF THE INVENTION 
   This invention relates to voice transcribing and print out of the transcribed message, and particularly to an integrated, hand held transcriber and printer unit especially adapted to permit a physician to dictate a medical prescription into the unit and that will print out a hard copy of the prescription while the unit is held in the doctor&#39;s hand. 
   BACKGROUND OF THE INVENTION 
   Potentially serious and untoward medical problems can occur when a pharmacist inadvertently dispenses a wrong drug because of inability to read what is often virtually illegible handwritten medical prescriptions. The present invention provides an alternative way to create accurate and legible medical prescriptions to ensure that drugs are dispensed as prescribed. This greatly benefits pharmacists and patients alike. Computerized medical prescription creation and management systems have been proposed in the past, but these systems have not found wide-spread acceptance because they have been time consuming and often required input into multiple computers or transfer of data into other computers before the prescription was complete. In view of the fact that time constraints are of importance to medical personnel, this invention serves to make the prescription completion process as quick and efficient as possible through the use of a hand held, self-contained device. 
   The invention applies speech recognition software to convert the voice input of the medical personnel into a printed prescription. Voice and sound recognition devices are disclosed in: U.S. Pat. No. 5,812,882 issued Sep. 22, 1998; U.S. Pat. No. 5,729,694 issued Mar. 17, 1998; U.S. Pat. No. 4,435,617 issued Mar. 6, 1984; and U.S. Pat. No. 4,392,409 issued Jul. 12, 1983. Prior prescription creation and management systems are described in patent Nos.: U.S. Pat. No. 5,845,255 issued Dec. 1, 1998; and U.S. Pat. No. 5,737,539 issued Apr. 7, 1998. 
   SUMMARY OF THE INVENTION 
   This invention concerns a hand held medical prescription transcriber and printer as an integrated unit. The transcriber records the words spoken by the user and then utilizes speech recognition software to convert the recorded sound into text. The device then formats the text for printing and prints it out as a hard copy on paper. The device is entirely self-contained because it incorporates an internal power supply and printer in the hand held unit. These features contribute to the simplicity and ease of operation, as well as the speed at which it functions. 
   In a preferred embodiment, the prescription transcriber and printer unit includes a voice responsive input device which converts the user&#39;s spoken word acoustic inputs into analog signals. A converter converts the analog signals into corresponding outputted digital signals. A database of medical prescription information is provided which stores a library of drugs and dosage regimes in digital format. A combination of digital signal and digital data matching code segments define a program which is operable to match outputted digital signals from the converter with corresponding digital data stored in the database. Additional code segments present components for retrieving the digital data stored in the database which matches the digital signals outputted from the converter and also serve to format the retrieved digital data from the database into a form representative of a medical prescription and dosage instructions. A printer incorporated into the unit receives the formatted digital prescription drug and dosage instruction data and prints out the prescription information as readable hard copy that can be handed to the patient at the time of prescribing of a drug. 
   In one form of the invention, the device is very simple, with only one “record” button which the user employs to start and stop the voice recording. Upon completion of recording, the device automatically processes the spoken words and prints the prescription as hard copy. In another form, the unit includes a voice activated input device, along with a small liquid crystal display screen on which the prescribed drug including dosage information is displayed prior to print out of the prescription. This form may if desired also include a manually manipulable dial which the user employs to scroll through a list of drugs contained in the language database in order to correct mistakes which might occur during the speech recognition process, or to select an alternate drug with similar therapeutic properties. 
   A still further form of the invention provides for electronic communication between the hand held device and another stand alone computer, thereby permitting the user to update the database of drugs and/or dosing instructions as, for example by accessing an updated list stored on the remote computer and then downloading that list onto the hand held medical prescription transcriber. 
   Data storage means may be provided in the hand held transcriber and printer unit which serves to store the data representative of each prescription and dosage information as it is written as a history of prescriptions prescribed over a pre-determined period of time, thereby permitting that historical information to be downloaded to a separate data storage site. 
   Although speech recognition software may be incorporated in the prescription transcriber and printer unit which recognizes and processes more complex information than a list of drugs and dosage instructions therefor, such as the patient&#39;s name and address, in most instances it is simpler for the physician to write the patient&#39;s name on the hard copy print out after the prescription is printed and delivered from the hand held unit. The principle purpose of the present invention is to avoid mistakes by a pharmacist who is unable to read the doctor&#39;s drug and dosage instructions thereby causing a prescription filling error. This problem normally does not occur in connection with patient&#39;s name and address because that information can be provided by the patient and verified by the pharmacist at the time the prescription is presented for filling by the pharmacist. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows an external representation of the invention in its preferred embodiment. 
       FIG. 2  is a simplified block diagram showing the components of one embodiment of the invention; 
       FIG. 3  is a software or firmware block diagram setting forth central processor activity during the flow of the operating system for the device in the embodiment of FIG.  2 . 
       FIG. 4  is a software or firmware block diagram setting forth the flow functions of the speech recognition program. 
       FIG. 5  is a software or firmware block diagram setting forth the flow functions of the prescription formatting and printing program. 
       FIG. 6  depicts an external representation of the invention in an alternative embodiment, which includes a liquid crystal display as an additional output device, along with controls for modifying the prescription, and a long-term storage chip; 
       FIG. 7  is a simplified block diagram showing the components of an alternative embodiment of the invention, which includes a liquid crystal display as an additional output device, along with controls for modifying the prescription and a long-term storage chip; 
       FIG. 8  is a software or firmware block diagram indicating central processor activity setting forth the flow function of the operating system for the device in the alternative embodiment shown in  FIGS. 6 and 7 ; 
       FIG. 9  is a simplified block diagram showing the components of a further embodiment of the invention, which includes a liquid crystal display as an additional output device, controls for modifying the prescription output, a long-term storage chip, and components permitting updating of the language and prescription database software from an external source. 
   

   DETAILED DESCRIPTION 
   I. Preferred Embodiment 
     FIG. 1  depicts an external representation of a hand held medical prescription transcriber and printer unit  10  in its preferred embodiment and that contains all of the components that are necessary for the most useful and efficient operation of the device. Externally, the only features of the unit  10  visible to the user are the case  12 , the microphone  14 , the light-emitting diode (LED)  16 , the manually operable controller  18 , the long-term storage (Flash Memory Card)  20 , the printer  22 , and the paper  24  which is discharged from printer  22 . The simplicity of the preferred embodiment of the invention assures compactness of the unit and maintains the efficiency of the device for the user. 
     FIG. 2  is a block diagram showing the internal arrangement of the components of the embodiment of FIG.  1 . Unit  10  internally contains a power supply  26  connected to an associated circuit board  28 . The case  12  is desirably formed from a synthetic resin material to present standard, injection-molded plastic “clam shell” construction, or alternatively, fabricated utilizing conventional manufacturing techniques and materials to provide a suitable impact-resistant and sturdy housing for the internal components. Case  12  is constructed of a size and shape to ergonomically permit the user to hold and operate unit  10  while held with one hand. 
   Case  12  has appropriate internal attachments such as screw holes or pockets, for mounting the internal components of unit  10 , including the power supply and circuit board  28 , as well as an internally mounted printer  22 , a supply roll of thermal paper  24  in the printer, a microphone  14 , and an On-Off switch  18  functioning as a controller for operation of the unit  10 . Case  12  is provided with openings in the wall structure thereof in a position allowing for voice sound waves created by the physician&#39;s voice during operation of unit  10  to reach and be sensed by the microphone  14 . An On-Off LED indicator  16  is mounted on the case  12  in disposition to permit ready viewing thereof when the unit  10  is held in its operating position by a physician. A suitable slot is provided in a sidewall of case  12  to permit ejection of paper  24  from the roll thereof. Another slot in a sidewall of unit  10  allows a storage device such as a Flash Memory Card  20  to readily be inserted and removed from the case  12 . A normally closed battery compartment has a removable or swingable closure permitting insertion and replacement of the batteries making up a part of power supply  26 . 
   Power supply  26  consists of a battery or an adequate number of batteries to provide required voltage and current to operate the electrical and mechanical components of unit  10 . In addition, voltage and current regulating hardware is incorporated in the power supply to assure that correct voltage or voltages and currents are continuously supplied to the various electrical and electronic hardware components forming a part of the prescription transcriber unit  10 . The power supply  26  may consist of a power supply system consisting of rechargeable batteries (e.g., lithium ion batteries), an integrated battery recharger powered by external DC power input, an appropriate input for the DC power, and the associated voltage and current regulating hardware required to deliver the correct voltage or voltages and currents. 
   Microphone  14  may be a standard device of the type that is operable to convert the acoustic inputs created by the user&#39;s voice into analog electrical signals during use of unit  10 . The acoustic inputs are represented diagrammatically in  FIG. 2  by the function block  30  of FIG.  2 . 
   The microphone  14  is preferably powered by the power supply  26 . In the preferred embodiment, controller  18  represents a simple single pole single throw switch (i.e., on/off) having a finger operable switch operator normally biased toward the open position of the switch. Depressing the switch operator against the spring bias thereon effects closing of the switch contacts, while letting up on the operator results in opening of the switch contacts. 
   Alternatively, the controller  18  may be in the form of voice-activated switch which closes upon receipt of a close-range acoustic input by a physician speaking into the microphone  14 . Desirably, the voice-activated switch is of the type which responds to sound emanating in close proximity to the device, such as a person speaking directly into the device, but that does not respond to distant noise, such as conversations elsewhere in the same room. A voice-activated switch normally is practical only in relatively well controlled and quiet environments, without a lot of background noise. A desirable low noise environment is usually present in physician&#39;s offices and in hospitals. 
   The circuit board  28  contains all of the electronics and programs required for operating the handheld medical prescription transcriber, including the analog-to-digital converter (A/D)  32 , the central microprocessor unit  34 , the operating system module  36 , the speech recognition integrated circuit module  38 , the prescription formatting software module  40 , the language and prescription database  42 , the removable long-term data storage card  20 , and random access memory (RAM) chip  44 . The circuit board  28  is of standard construction consisting of laminations of plastic and copper etched to provide proper electrical circuit connections between the various electronic components which are attached to the circuit board  28 . 
   The circuit board  28  and all the components attached thereto are powered by the power supply  26 . The A/D converter  32  converts the analog signal produced by the microphone  14  into a digital signal which can be sampled by the central microprocessor unit (CPU)  34 . The CPU may be a standard microprocessor such as those typically used for notebook computers. However, the CPU must be relatively fast in order to efficiently process the speech recognition programs. A practical implementation of the device utilizes for example a notebook Pentium III processor manufactured by Intel, ranging from the 600 MHZ up to the 850 MHZ chip. 
   The CPU  34  processes the digitized voice input it receives from the A/D converter  32  by utilizing instructions and data contained in the operating system module  36 , the speech recognition module  38 , the prescription formatting module  40 , and the language and prescription database  42 . The language and prescription database  42  desirably contains all the words and speech recognition data (i.e., acoustical statistics) required by the speech recognition module  38  and prescription formatting module  40  to operate properly. The digital information contained in database  42  is stored in the long-term storage memory card  20 . 
   The information contained in database  42  stored in card  20  may be limited to a subset of the English language plus all the drugs contained in such standard references as the Physicians Desk Reference. The limited subset of English consists of only words necessary for dispensing prescriptions, including numbers, and words associated with dosages (e.g., “milligram”, “tablets”, etc.), frequency (e.g., “per day”), duration (e.g., “for seven days”), and administration instructions (e.g., “by mouth”). This constitutes only a few thousand words, as opposed to in excess of at least one hundred thousand words required for a competent spoken English recognition system. The limited amount of words and numbers that must be stored and made accessible, significantly decreases the amount of actual information that must be stored in the database card  20 . 
   Furthermore, the digital data stored in database  42  can be arranged by conventional software into categories in order to assist the prescription formatting module  40  in converting the spoken words into a prescription format  40 . In view of the fact that some words may be included in more than one category, in addition to all the words, the database should also store characteristic acoustical statistical information about each word. This information in digital format is required by the speech recognition module  38  in order to efficiently convert the digitized spoken words into text. 
   The long-term data storage card  20  desirably is a rewritable long-term electronic storage media such as a Compact Flash Memory Card which can be easily removed and replaced or reprogrammed for frequent updating. Since new drugs are frequently and constantly being introduced to the market, the database must be easily updated. A Flash Memory Card is preferred for this application. These are widely available from many suppliers. A 64 MB Apacer ATA Flash Memory Card is adequate in most instances. This card is in the PCMCIA format and is of a type that is accessible from the outside of the transcriber and can be removed and replaced by another card provided by a supplier and containing an updated database of drugs. Alternatively, the user can update the contents of the Flash Memory Card  20  by putting it in a separate device attached to a personal computer. 
   The operating system module  36  contains all the instructions (i.e., programs) required by the device to operate properly. The operation of transcriber and printer unit  10  can best be understood from the diagrammatic flow chart of FIG.  3 . The OS module  36  consists of the operating system program code  46  and an appropriate storage unit  48  for this code. The operating system module  36  preferably provided as a “firmware” module wherein the program code  46  is hardwired or “burned” into an integrated circuit (i.e., a chip) as the storage module  48 . The use of an integrated circuit chip such as a Programmable Read Only Memory module  48  (PROM) ensures the most rapid loading and processing of operating system commands by the CPU  34 . Since the speed of operation of unit  10  is essential to its convenience, rapid loading and processing of data is desirable. PROM&#39;s are widely available in a variety of capacities and from a variety of vendors. The IC chip can either be hardwired to circuit board  28  or it can be installed into a socket attached to the circuit board such that it can be replaced in order to upgrade the operating system. As an alternative arrangement, the storage unit  48  may comprise a small part of the long-term storage  20 . This allows the operating system to be periodically updated. 
   The speech recognition module  38  contains all of the instructions (i.e., programs) required by the unit  10  to process the words spoken by the physician and received by the microphone  14  which are then converted into written text. The speech recognition module  38  consists of the speech recognition program code  50  and an appropriate storage unit  52  for this code. This module  38  may be in the form of a “firmware” module wherein the program code  50  is hardwired into an integrated circuit chip which also serves as the storage module  52 . The use of an integrated circuit chip as module  38  again ensures the most rapid loading and processing of speech recognition commands by the CPU  34 . Since the speed of operation of this device is essential to its convenience, such rapid loading and processing is desirable. The IC chip  38  can be hardwired to the circuit board  28  or it can be installed in a socket attached to the circuit board such that it can be replaced in order to upgrade the speech recognition software. As a farther alternative, the storage unit  52  could represent a part of the long-term storage device  20 , thus allowing the speech recognition software to be upgraded periodically in the same manner as the prescription database  42 , as described above. 
   The prescription formatting module  40  contains all of the instructions (i.e., programs) required by the device to format the text produced by the speech recognition program into a form representative of a medical prescription and which can be printed by the printer. The prescription formatting module  40  consists of the prescription formatting program code  54  and an appropriate storage unit  56  for this code. This module  40  may also be provided as a “firmware” module in which the formatting program code  54  and the storage unit  56  are both hardwired into an integrated circuit chip. The IC chip can be hardwired to the circuit board  28  or it can be installed in a socket attached to the circuit board such that it could be replaced in order to upgrade the formatting module  40 . The storage unit  56  could if desired be a part of long-term storage unit  20 , thus allowing periodic upgrading of the formatting program. 
   Random Access Memory (RAM)  44  is required by the CPU  34  in order to temporarily store data, such as the digitized speech, and the program instructions. In order to properly run the speech recognition programs, at least 32 MB of RAM and preferably 64 MB of RAM is required. Standard RAM can be used. For the most practical and compact implementation of unit  10 , 64 MB of SDRAM in one 72-pin DIMM may be utilized. 
   The printer  22  creates an easily readable printout of the medical prescription  58  (FIG.  2 ). The printer must be compact enough so that it can easily fit in a hand held device. Such printers are now in widespread use in a variety of compact, portable electronic devices. The printer  22  that is used for the preferred embodiment of this invention is the Densitron DPTH 804 Thermal OEM Printer. This thermal print head printer  22  has the ability to print bar codes, text, and graphics and is very capable for use in mobile, handheld devices due to its compact size. The printer  22  includes a high performance processor, battery, and print mechanism. 
   The paper source  24  can be a roll of standard thermal paper appropriate for use by the printer  22 . The user can employ if desired thermal paper with preprinted prescription forms including the doctor&#39;s name, medical identification number, and other desired information. 
   The long-term storage  20  included in the preferred embodiment also provides for the recording of a number of prescriptions for future printing, or for input into a patient&#39;s records. The entering of the prescriptions into the long-term storage  20  is automatic and occurs simultaneously with printer. The device&#39;s CPU  34  writes the prescription data directly to the long-term storage card  20 . The stored prescription records can be downloaded to a personal computer later by removing the Flash Memory Card  20  from the transcriber and reading it with a separate device attached to the personal computer. The long-term storage  20  also provides for downloading customized prescription forms into the transcriber. Again, using a separate device attached to a personal computer, the user can save electronic forms on the Flash Memory Card  20  to be used by the operating system when printing the prescription. In this manner, various customized information can be automatically printed on the prescription. 
   II. Operating System Software Flow of Unit  10   
   The overall software flow function of the medical prescription transcriber and printer unit  10  that is implemented via the operating system module  36  for the preferred embodiment of the device is shown diagrammatically in FIG.  3 . In the preferred, simplest embodiment of the unit  10 , the device has four modes: Ready Mode  100 , Processor Mode  102 , Standby Mode  104 , and Print Mode  106 , with activation of the unit being controlled by movement of the manual control switch  18 . 
   Prior to activation of the voice recording controller function  108  by actuation of switch  18  as shown diagrammatically in  FIG. 3 , the device remains in ready mode  100 , a passive state. The ready mode state  100  of unit  10  is indicated by illumination of the green LED as shown in the flow chart of FIG.  3 . 
   Upon pressing of the manually operable control switch  18  to render the controller function  108  active, the device moves into processor mode  102 . Shifting of the operative condition of unit  10  from ready or standby mode  100  to processor mode  102  is indicated to the user by changing of the color of the LED to yellow  110 . In processor mode  102 , the CPU begins to sample the analog to digital signals from analog/digital converter  32  at a specified sample rate indicated by processor function block  112  of FIG.  3 . In a preferred implementation of this invention, a sample rate of approximately 10,000 times per second is used. The processor  34  formats the digital signals received from the A/D converter  32  and writes the formatted data to RAM  44  as indicated by function block  114  of FIG.  3 . When approximately 10 milliseconds of data have been recorded to RAM  44 , the processor  34  also loads the speech recognition software from the speech recognition integrated circuit chip  38  and begins to perform the speech recognition algorithm as indicated by function block  116  of FIG.  3 . 
   As long as the speech recognition process proceeds smoothly as indicated by function block  118 , the controller  108  remains active as indicated by function block  120 , the processor  34  continues to sample the digital signals from A/D converter  32  and continues to write data to RAM  44 . If at any time the speech recognition software submits an error message as output, the processor  34  will stop sampling the A/D and the unit  10  will enter Standby Mode  104 . The color of the LED will change to red as indicated by function block  122 , as an indication to the user that an error in processing has occurred. 
   When the manually manipulable switch  18  is released to deactivate controller function  108 , the device will return to Ready Mode  100 . The color of the LED will return to green, as an indication to the user that the device is ready to start recording again. The only reason that the processor  34  would send such an error message is because a word spoken by the user could not be recognized as being in the database of module  38 . This is not a likely occurrence given the relatively small size of the database of words required for the medical prescription transcriber. 
   If the speech recognition process proceeds without submitting an error message, the processor  34  will continue to sample the output from A/D converter as indicated by function block  112  and to write data to RAM  44  until the user releases the switch  18  causing the speech recording controller function  120  to cease operation. Upon release of the controller active function as indicated by function block  120 , the unit  10  moves into Print Mode  106 . Print Mode  106  is indicated to the user by changing of the color of the LED to orange as represented by function block  122 . In Print Mode  106 , the processor  34  loads the prescription database information from card  20  and formatting software from module  40  and formats spoken text which has been matched with drug, dosing instructions, and other stored data from the prescription, dosing instruction and other word database from the prescription and language database for printing out on printer  22 . 
   If the spoken text cannot be properly processed for printing as a prescription, an error message will be sent by the prescription formatting software. The processor will stop the A/D sampling function  112  and the device will enter Standby Mode  124 . The color of the LED will change to red as represented by function block  126 , as a sign to the user that an error in processing has occurred. After a brief (e.g., 2 or 3 second) pause, the device will return to Ready Mode  100 . 
   Once the text has been processed as indicated by function block  128 , the formatted data, including any previously downloaded customized forms, will be submitted to the print driver, which will in turn send it to the printer  22 , which will print out prescription as represented by function block  130  of FIG.  3 . This completes the cycle, and the device is returned to ready mode  100 . 
   III. Speech Recognition System 
     FIG. 4  illustrates the software flow function of the speech recognition module  38 . The processor  34  which calls the speech recognition program from module  38  directs digitized speech, identified by function block  200 , into RAM  44  for storage. The processor  34  divides this speech into separate pieces as indicated by function block  202  with each frame or piece being approximately 10 milliseconds in length. Each of these pieces is a frame. For each frame of speech, the speech recognition software conducts a complex spectral analysis and computes several spectral features identified by function block  204  of the  FIG. 4  flow chart. In a preferred embodiment, these spectral features include twelve mel-frequency cepstral coefficients (MFCC), twelve coefficients indicating the degree of change of the MFCCs, one energy feature, and one feature indicating the degree of change of energy. Such spectral analysis is carried out in accordance with standard techniques. 
   Once the spectral features for a given frame are calculated, the values for those features are classified as to phonetic category as indicated by function block  206 , and then compared to values for those features for the various phonemes and subphonemes in the language database  42 , as indicated by function block  208 . 
   Phonemes are the simplest elements of spoken language. For example, in English, the sound “ee” is a phoneme. There are a finite number of phonemes in each language. However, the spectral characteristics of each phoneme can vary depending upon the placement of that phoneme relative to other phonemes in spoken language. Therefore, it is often necessary to consider subphonemes which comprise an entire phoneme. 
   Because the spectral features of a given phoneme or subphoneme will vary depending upon who is saying the word, it is often not possible to definitely determine which subphoneme a certain frame represents. Instead, a probability is assigned to the association of the frame with given phonemes. For example, if a speaker says the drug name “Xanax”, the first phoneme is the sound “Z”. Depending upon how it is said, the software may determine a high probability (e.g., 85%) that this frame represents the sound “Z” and a lesser probability (e.g., 15%) that it represents the sound “S”. In this manner each frame is classified. 
   The phoneme and subphoneme classifications of each frame are then assembled, and those series are compared to the series of phonemes associated with the various words in the language database. Since each frame is associated with several phoneme matches with varying probabilities, a series of frames corresponds to a number of potential combinations of those subphonemes and phonemes with varying probabilities. Those combinations are compared to the combinations for words in the language database  42 , and using this process, the software can determine the probability that the speaker spoke one of several target words. 
   In a very large language database, such as the entire English language, there are often many possible target words, and depending upon the clarity with which the speaker says his words, the probabilities associated with several target words may be nearly equal. This makes speech recognition challenging. In the present invention, however, the language database  42  is significantly smaller than the entire English language. This assures an almost 100% certainty of a correct match being made of written text to spoken text. 
   Once a match for a given word is made, the probability (confidence) associated with that word is examined as indicated by the measure of confidence function block  210 . If the probability exceeds a specified threshold (e.g., 80%), the word will be accepted as indicated by function block  212 . If the probabilities associated with all target words fall below the threshold, but if the probability associated with one of the words is significantly higher than that associated with the next best choice, the word is accepted. If the probabilities associated with all target words are small and similar, then all words are rejected and the system has not successfully recognized the spoken words. This will occur if (1) the speaker says words not in the database, (2) the speaker speaks very poorly (e.g., mumbles, coughs, etc.), or (3) the spoken words are mixed with significant background noise. The first case should not occur so long as the database of drugs is regularly updated, and the other two cases are easily avoided by the user. 
   Once a successful match is made as indicated by function block  212 , the speech recognition software will continue to process the digitized speech until it has processed all of the data submitted for analysis as indicated by function block  214 . The various word matches will then be assembled into the complete text spoken by the user. This text is then stored in RAM  44  as indicated by function block  216  and outputted as text pursuant to function block  218  to be processed for display, editing, or printing. 
   IV. Prescription Formatting 
   The software flow functions of the prescription formatting module  40  for the preferred embodiment is schematically illustrated in FIG.  5 . The full text as produced by the speech recognition software and represented schematically by the function block  200  in  FIG. 5  is divided into an array of words as indicated by function block  202 . First, the software searches the words for names of drugs as represented by function block  204 . If no drug name is found, pursuant to function block  206 , the software submits an error message represented by output block  208  and exits. When a drug name is identified, in function  206 , the drug name is stored in a field identified as function block  210  in RAM  44 . The software then continues to search through the array of words for words associated with dosage indicators as represented by function block  212 . The software is preferably programmed to recognize the full range of anticipated phrases used to indicate dosage as represented by function block  214 . These would primarily include weight of active medicament, e.g. mg., or meg., or measurements of volume, such as milliliters, teaspoons, etc., but might also include many other measurements. For some drugs, such as ointments, dosages might be more qualitative, and this would need to be included in the software. If no dosage data or equivalent is found, the software would again exit with an error message  208 . 
   If terms for the prescribed dosage are found, these terms are stored in another field as represented by function block  216  in RAM  44 . The software similarly may, if necessary, search for, find and store digital data representing words associated with drug administration, words associated with frequency of dosage, and terms associated with duration of the individual prescription, which are represented by the sequential function blocks  218 ,  220 ,  222 ,  224 ,  226 ,  228 ,  230 ,  232  and  234  of FIG.  5 . When all of these terms are successfully identified, the five fields for (1) drug name, (2) dosage, (3) delivery instructions, (4) frequency, and (5) duration are assembled and formatted as indicated by function block  236 , and sent to the print or display driver as represented by function block  238  which outputs appropriate digital data  240 . 
   V. First Alternative Embodiment with Visual Display and Editing Capability 
     FIG. 6  is an external representation of in an alternative transcriber and printer unit  310 , which adds to a video display the transcriber and printer unit  10  that allows a user to view the prescription and also provides a means for editing the prescription before printing. Externally, the only features of the transcriber and printer unit  310  visible to the user are the case  312 , the microphone  314 , the liquid crystal display (LCD)  360 , the recording controller  318 , a control  362  for editing the prescription, the print control  364 , the Flash Memory Card  320 , the printer  322 , and the paper  324 . Unit  310  remains simple to use while adding to the functionality of the unit. 
     FIG. 7  is a block diagram showing the internal set-up for the transcriber and printer unit  310 . The internal components of unit  310  are identical to those of unit  10  as shown in  FIG. 2 , with the exception of components which provide for the display of the prescription information for visual observation by the physician prior to initiating printing of the prescription. There is no LED  16  in unit  310  in view of the provision of the LCD  360 . 
   The edit control  362  and print control  364  are added components in unit  310 . Furthermore, the operating system module  336  in unit  310  and the prescription formatting module  340  are different from their counterparts in unit  10 . 
   The LCD  360  provides a convenient way for the user to verify that the results of the speech recognition analysis are correct. The LCD  360  visually displays the results of the software analysis of the physician&#39;s spoken words for verification of accuracy of the information before it is printed out by printer  322 . The LCD  360  receives digital information directly from unit  310 &#39;s CPU  34 . The LCD  360  serves as a backup for the speech recognition software to permit confirmation of the accuracy of the speech recognition before printout of a prescription. 
   The LCD  360  of unit  310  may for example comprise an alphanumeric display available from Seiko Instruments. This type of LCD display is advantageous in that it is thin, lightweight, and requires low power. The display has a relatively wide viewing angle making the image displayed on the screen easy to view by the user of the unit. 
   The edit control dial  362  forming a part of unit  310  allows for selective modification of the speech recognition analysis after the user has viewed the results on the LCD display  360 . After the user of unit  310  has spoken the words making up a prescription, at least the name of the drug will appear on the screen of the LCD. The physician can use the dial  362  on the side of case  312  to scroll through drugs in the database. If the drug name needs to be changed or corrected, this can quickly be done with control  362 . The rotatable control  362  is operably connected to the CPU  34  and allows the processor  34  to display on the LCD  360  a choice of possible alternative drugs when the user requests that information. The language and prescription database software  42  generates this choice of words. The user can scroll down the list of alternative words and select the desired drug. The processor  34  can also display similar drugs or drug brand names when prompted by the user, giving the user access to other prescription and drug information that may aid in the accurate completion of the prescription. The user can then quickly correct any mistakes in the analysis and continue on with the printing of the prescription output indicated by function block  366  in FIG.  7 . This procedure significantly decreases the possibility of mistakes in the printed output  366 . The control  362  also offers the option to have the device continue on with the printing of the prescription. As can be seen in  FIG. 7 , the control  362  connects directly to the CPU  34 , allowing the processor  34  to adjust the output on the LCD  360  accordingly. Again referring to  FIG. 7 , print control button  364  is required in unit  310  in order to control printing upon completion of the editing. This button preferably consists of a simple on/off switch. 
     FIG. 8  schematically represents the overall software flow functions of unit  310  which are implemented via the operating system module  336 . In this alternative embodiment, the unit  310  has six operating modes represented by function blocks Ready Mode  400 , Processor Mode  402 , Error Mode  404 , Display Mode  406 , Edit Mode  408 , and Print Mode  410 . Ready Mode  400  and Processor Mode  402  function the same as Ready Mode  100  and Processor Mode  102  as previously described with respect to unit  10 . The Error Mode represented by function block  404  replaces Standby Mode function block  104 . In the event the speech recognition is not successful as represented by function block  412 , the speech recognition software initiates an error message represented by function block  404  and an error message is displayed on the LCD  360 . The unit  310  remains in Error Mode  404  until the user releases the record controller  318 . 
   When the Processor Mode  402  successfully completes speech recognition function  412 , the unit  310  moves into Display Mode function  406 . The prescription formatting software formats the text for display in the same manner described and illustrated with respect to the flow diagram of FIG.  5 . When the text has been successfully formatted for display as indicated by function block  414  of  FIG. 8 , the text is displayed in prescription format on the LCD  360  as indicated by function block  416 . If customized prescription formats have previously been downloaded into the memory of unit  310 , then the forms may be displayed on the LCD  360  as well. 
   After the text has been displayed as indicated by function block  416 , the processor  34  continues to check the Edit Control  418  and Print Control  420  for activity. If the Edit Control function  418  is active, the unit moves to the Edit Mode function  408 . If the print control  420  is active, the unit moves to Print Mode  410 . 
   In Edit Mode  408 , the physician uses the prescription edit control  362  if desired to scroll through the database of drug names as indicated by function block  422 . The LCD  360  displays the drug name in a window indicated by function block  424  in FIG.  8 . The window  424  may for example display the selected drug name as well as the two drugs which alphabetically appear just before and just after the selected drug. The selected drug would appear in the middle, highlighted. The physician may employ the Edit Control  362  to scroll up or down through the database of drugs indicated by function block  422 . The drug appearing in the middle would always be highlighted, indicating that it is the selected drug. This Edit Mode  408  can be used by the physician to select another drug in the event that the speech recognition software mistakenly identified the wrong drug based upon the words spoken by the user. The Edit Control  362  sends a signal to the processor  34 , which in turn updates the LCD  360  and updates the record stored in the RAM  444 . 
   Once the desired drug is selected, whether Edit Mode function  408  is employed or not, the physician may then activate the Print Control function  420 , thereby moving the device into the Print Mode function  410 . 
   In Print Mode  410 , the processor  34  formats the prescription data for printing as indicated by function block  426 , including the use of any downloaded customized forms and submits the data to the print driver which in turns sends it to the printer represented by function block  428 . Simultaneously, the processor  34  also writes the prescription record to long-term memory  430  for future reference. 
   VI. Second Alternative Embodiment with External Communications Capability 
     FIG. 9  is the block diagram for another alternative embodiment of the transcribing and printing unit. This embodiment  510  provides for updating any of the software or data stored in long-term memory via an external update connection represented by function block  512 . For practical implementation, the external update connection  510  preferably consists of an RS-232 serial connector which allows the user to connect the handheld medical prescription transcriber unit  510  to a personal computer. In this manner, download upgrades may be made to the speech recognition program module  38 , the language and prescription database  42 , the prescription formatting module  40 , or the operating system module  36 , and allow for uploading of prescription records stored in the long-term storage card  20 . The connection can also be used to download preprinted electronic versions of forms into the memory for printing on every prescription, such as customized forms used by the user. Other than adding the external update connection, the only other difference between unit  310  and unit  510  is the change in the operating system modules. The operating system module  514  of unit  510  is the same as the operating system module  336  of unit  310 , except that the operating system program code  516  of module  514  differs from the operating system program code  346  of unit  310  to allow the external communications. 
   The benefit of this external upgrading of the software programs and data stored in unit  510  is the fact that one would not have to remove the long-term storage device  20 , such as a Flash Memory Card, and update this card using separate hardware attached to a personal computer, in order to update the database  42 , or any of the programs  46 ,  50  and  54 , therefore significantly simplifying this necessary process. It would allow for more frequent updating of the database  42  because of the ease with which this process can be done. Furthermore, provision for external upgrading of programs and the database reduces the overall cost of the device because the removable Flash Memory Card could be replaced with a less expensive internal Electrically Erasable Programmable Read Only Memory (EEPROM). The EEPROM would not require removal from the transcriber in order to update its contents. EEPROMs are available in a wide variety of capacities from a variety of vendors. This updating capability may be deemed necessary due to the frequent development and use of new drugs and drug brands. Unit  510  operates in the same manner as previously described in connection with unit  310 .