An ambulatory electrocardiographic apparatus

Abstract: An ambulatory electrocardiographic apparatus is disclosed which comprises a main body; at least one RAM (13) capable of storing not only various programs for analysis and recording of the electrocar­ diographic signals detected but also the electrocardiographic sig­ nals detected and the results of the analysis thereof; a card moun­ ting section provided on the main body, into which a IC memory card (4) can be inserted detachably from the main body; a control unit (11) for analyzing the detected signals in accordance with a program stored in the IC memory card (4) and for allowing the processed data to be stored in the IC memory card; and a display means (2) for provi­ ding a display of the detected signals and the data stored in the IC memory card.

Description: BACKGROUND OF THE INVENTION 1. Field of the invention: This invention relates to an ambulatory electrocardiographic apparatus by which the electrocardiographic signals detected from a subject can be recorded and analyzed without any restraint on the subject for a long period of time. More particularly, it relates to an ambulatory electrocardiographic apparatus which is provided with an IC memory card detachable from the main body of the apparatus, wherein the electrocardiographic signals detected can be analyzed in accordance with a program stored in the IC memory card; the results of the analysis, together with the electrocardiographic signals, can be stored in the IC memory card; and these data can be given on a display means of the main body. 2. Description of the prior art: In conventional ambulatory electrocardiographic apparatuses, the electrocardiographic signals detected and the results of the analysis thereof are first stored in a storage medium such as a magnetic tape mounted on the main body of the apparatus. When the recording is complete, the storage medium is dismounted from the main body and then set on an analyzing unit which is provided separately from the main body. The data stored in the storage medium are analyzed in accordance with a program for analysis stored in the analyzing unit. The results of the analysis are given on a CRT display unit or a printer connected to the analyzing unit. In the Japanese Laid-Open Patent Publications No. 49-20981, No. 49-27087, and No. 51-90784, there are disclosed compact, light-weight ambulatory electrocardiographic apparatuses in which recording and replaying of electrocardiographic signals are performed in the same mechanism by the use of a magnetic tape as the storage medium. The Japanese Laid-Open Patent Publication No. 58-19229 discloses an ambulatory electrocardiographic apparatus which is capable of recording for a long period of time by the use of a detachable magnetic bubble memory as the storage medium. In this apparatus, the electrocardiographic signals detected are compressed and stored in the bubble memory. The Japanese Laid-Open Patent Publication No. 59-222129 discloses an ambulatory electrocardiographic apparatus in which an IC memory is utilized as the storage medium. In this apparatus, different patterns of the electrocardiographic waveform detected are all marked with symbols and registered in a pattern table, so that memory capacity required for recording electrocardiographic signals for a long period of time can be considerably reduced by recording only the symbols with respect to the electrocardiographic waveform of the different patterns. The Japanese Patent Application No. 63-65246 discloses an ambulatory electrocardiographic apparatus comprising a memory means, a memory control means, and a data-holding control means, wherein the electrocardiographic data are renewed and stored sequentially with time, so that only the electrocardiographic data necessary for analysis can be obtained with high efficiency and reliability. When analyzing electrocardiographic signals, it is desirable to change the methods for analyzing and recording the electrocardiographic signals depending upon the kind of disease, the condition of the disease, the difference in medical treatment, and other conditions. However, such an elaborate analysis with the above-mentioned conventional recording and analyzing system requires a change in the program stored in the analyzing unit every time the analyzing and recording methods are changed. For this reason, not only is the number of ambulatory electrocardiographic apparatuses greatly restricted by the number and processing capability of analyzing units, but also minute analysis cannot be carried out speedily and readily. Moreover, it is desired to reduce the size and weight of electrocardiographic because these apparatuses are carried by respective subjects at all times. The same as just discussed is valid for an ambulatory electrocardiographic apparatus as it is described in WO-A-87/06447, and as it comprises the features of the preamble of claim 1. Every time, when the analyzing and recording methods are changed, a change in the program stored in the memory means is necessary. SUMMARY OF THE INVENTION It is the object of the present invention to provide an ambulatory electrocardiographic apparatus which is able to easily cope with different analyzing and recording methods. The apparatus of the present invention is defined by the teaching of claim 1. It is an essential feature of this apparatus that it comprises a memory card which stores not only detected and analyzed data, but also a program for detecting an analyzing data. Therefore, when the analyzing and/or recording methods have to be changed, only the IC memory card has to be changed. As different key operations may be necessary for different recording and/or analyzing methods, the apparatus of the present invention preferably comprises a transparent sheet-shaped keyboard according to claim 2, cooperating with an IC memory card having key symbols on its surface, or a detachably mounted key panel. BRIEF DESCRIPTION OF THE DRAWINGS This invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings as follows: Figure 1 is a perspective view showing an ambulatory electrocardiographic apparatus of this invention. Figure 2 is a perspective view showing another ambulatory electrocardiographic apparatus of this invention. Figure 3 is a block diagram of a circuit of the ambulatory electrocardiographic apparatus of this invention. Figure 4 shows an example of electrocardiograms given on a liquid crystal display device of the ambulatory electrocardiographic apparatus of this invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 shows an ambulatory electrocardiographic apparatus of this invention. In this figure, reference numeral 1 is a plurality of electrodes for detecting electrocardiographic signals, reference numeral 2 is a liquid crystal display device which displays the electrocardiographic signals, the results of the analysis thereof, and other information, and reference numeral 3 is a card mounting section into which an IC memory card 4 is inserted detachably. When the IC memory card 4 is inserted in the direction indicated by the arrow in this figure, electrodes of the IC memory card 4 come in contact with electrodes provided in the inside of the card mounting section 3, so that the IC memory card 4 and the circuit in the main body of the apparatus are electrically connected with each other. As used herein, the term "IC memory card" refers to a storage medium in the shape of a card. The IC memory card comprises a memory unit composed of read only memories (ROMs) and random access memories (RAMs), which are constituted by integrated circuits (ICs). The IC memory card 4 can store a program for analysis depending upon the kind of disease, the condition of the disease, and the particular medical treatment. In other words, different kinds of IC memory cards can store different programs for analysis, respectively. The IC memory card 4 can further store the electrocardiographic signals detected and the results of the analysis thereof. On the surface of the IC memory card 4, there is provided key symbols. On top of the card mounting section 3, there is disposed a transparent sheet-shaped keyboard 5. The transparent sheet-shaped keyboard 5 comprises, for example, a flexible, transparent plastic sheet having transparent electrodes arranged in X direction, and a transparent plastic substrate having transparent electrodes arranged in Y direction, both of which are formed into a laminated sheet with a plurality of small insulating buttons (shown by black dots in Figure 1) interposed therebetween. Therefore, when the IC memory card 4 is inserted into the card mounting section 3, the key symbols on the surface of the IC memory card 4 can be seen through the transparent sheet-shaped keyboard 5, allowing a key entry by pressing the portion of the transparent sheet-shaped keyboard 5 corresponding to the desired key symbol. Although the keys of the transparent sheet-shaped keyboard 5 are defined for each IC memory card 4 to be inserted, not much explanation will be needed because the technique for changing the definition of keys is well known. The transparent sheet-shaped keyboard 5 may be of various constitutions. For example, it may be composed of two transparent sheets with conductive projecting points arranged in matrix therebetween so that a contact state of the projecting point pressed with a finger can be monitored by a central processing unit (CPU) to determine which key has been pressed. Reference numeral 7 is a cover provided rotatably on the main body, which serves to open and close the section of the card mounting section 3 and the transparent sheet-shaped keyboard 5. Figure 2 shows another ambulatory electrocardiographic apparatus of this invention. The same parts as shown in Figure 1 are designated by the identical reference numerals. This ambulatory electrocardiographic apparatus is of the same constitution as mentioned above, except that the transparent sheet-shaped keyboard 5 provided on top of the card mounting section 3 is replaced with a separate key panel 6 mountable on this section. The key panel 6 is provided at one end with electrodes which can be connected electrically with the circuit of the main body, when the key panel 6 is inserted into the key panel mounting section, which is formed on the card mounting section 3, in the direction shown by the arrow in Figure 2. The key panel 6 is composed of two panels, which are provided with electrodes arranged in X and Y directions, respectively, and which are attached to each other with a spacer interposed therebetween. On the surface of the key panel 6, key symbols are printed. Figure 3 is a block diagram of a circuit of the ambulatory electrocardiographic apparatus of this invention. (The same parts as shown in Figures 1 and 2 are designated by the identical reference numerals. The electrocardiographic signals detected by the electrodes 1 are amplified in an amplifier 8 and converted to the corresponding digital signals in an A/D converter 9, followed by being fed into the central processing unit (CPU) 11. The electrocardiographic digital signals fed into the CPU 11 are recorded in a RAM 13 in accordance with a program and condition statements which have been written into a ROM 12 of the IC memory card 4. An example of recording conditions is as follows: When an event entry is made by a subject through the transparent sheet-shaped keyboard 5 or the key panel 6, only the electrocardiographic waveform is recorded for a period of 15 minutes before and after the entry. Alternatively, electrocardiographic signals are analyzed in accordance with the program stored in the ROM 12, and all that is recorded is that portion of the electrocardiographic waveform which is found to be disordered. Moreover, a mode of recording can be selected to meet the particular needs such as to record the heart rate per heartbeat, in order to detect an overall change in the pattern of electrocardiographic signals throughout a period when the apparatus is attached to the body of a subject. The conditions of finding a disorder of the electrocardiographic waveform and then automatically recording its data can be set in advance by the use of the transparent sheet-shaped keyboard 5 or the key panel 6 through the interactive operation with a message given on the liquid crystal display device 2. The electrocardiographic signals and the results of analysis recorded in the RAM 13 can be read out through the operation of the transparent sheet-shaped keyboard 5 or the key panel 6 and then given on the liquid crystal display device 2 via a liquid crystal display driver 10. Moreover, by the use of the transparent sheet-shaped keyboard 5 or the key panel 6 through interactive operation with a message given on the liquid crystal display device 2, whether a state of attaching the electrodes 1 to the body of a subject (i.e., a state of detecting the electrocardiographic signals) and the working of the apparatus are normal or not before and during the recording of the electrocardiographic signals can be checked by determining whether the signals collected by the CPU 11 include much hum components, or by writing the signals into the RAM 13 as they are and then reading them out to determine whether they correspond to the signals which have been written the RAM 13. Figure 4 shows an example of electrocardiograms given on the liquid crystal display device 2. In this example, a part of electrocardiographic signals recorded in the IC memory card 4 is given on the display screen of 64 dots in vertical line by 96 dots in horizontal line. With the use of such a display screen, various messages regarding the operation of the apparatus can also be given thereon. Although in the electrocardiographic apparatus mentioned above, the programs for analysis and recording are stored in the ROM 12 and the results of the analysis are recorded in the RAM 13, the memory unit of the IC memory card 4 can also be composed only of with RAMs so that various programs are written in the RAMs with the use of an external system comprising an IC memory card reader/writer, a personal computer, etc., thereby allowing the use of many kinds of programs in a single IC memory card. With a liquid crystal television connected to the apparatus, it is also possible to provide a display of electrocardiographic waveform with high resolution.

Claims: An ambulatory electrocardiographic apparatus comprising: a main body; electrodes (1) for detecting electrocardiographic signals according to a program; an analyzing means (11) for analyzing said detected electrocardiographic signals by using said program; a memory means (12, 13) for storing said detected signals, signals provided by said analyzis and said program; and a display means (2) for displaying the detected signals and the data stored in said memory means; characterized by a card mounting section (3) provided on said main body, for inserting an IC memory card comprising said memory means storing said data including said program. An ambulatory electrocardiograph apparatus according to claim 1, further comprising a transparent sheet-shaped keyboard (5), wherein when an IC memory card (4) having key symbols on the surface thereof is inserted into said card mounting section, said transparent sheet-shaped keyboard is arranged a top said key symbols. An ambulatory electrocardiographic according to claim 1, further comprising a key panel (6) for making a key entry associated with said IC memory card (4) and a key panel mounting section provided on the main body of the apparatus allowing said key panel to be mounted detachably. An ambulatory electrocardiographic apparatus according to claim 1, wherein said IC memory card (4) comprises at least one ROM (12) for storing various programs for analysis and recording, and at least one RAM (13) for storing the electrocardiographic signals detected and the results of the analysis thereof. An ambulatory electrocardiographic apparatus according claim 1, wherein said IC memory card (4) comprises at least one RAM (13) for storing not only various programs for analysis and recording but also the electrocardiographic signals detected and the results of the analysis thereof and wherein said programs can be rewritten with the use of an external system comprising an IC memory card reader/writer and a personal computer. An ambulatory electrocardiographic apparatus according to claim 1, wherein the function of said analysing means is performed by a central processing unit (11). An ambulatory electrocardiographic apparatus according to claim 1, wherein said display means (2) comprises a liquid crystal display device.

Inventors: SUZUKI TAKASHI, SUZUKI, TAKASHI
Applicants: SHARP KK, SHARP KABUSHIKI KAISHA
Application year: 1989
Main classification: A61B5
IPC codes: A61B5, G01D9