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Patent No. 6364834  Method and system for remotely monitoring multiple medical parameters in an integrated medical monitoring system (Reuss, et al., Apr 2, 2002)

Abstract

An integrated medical monitoring system comprising at least one patient monitor, at least one central monitor, and at least one remote access device which are tied together through an integrated communications link is disclosed. The communications between various components of the system are bi-directional, thereby affording the opportunity to establish monitoring parameters from remote locations, provide interactive alarms and monitoring capabilities, and provide data exchange between components of the system.

Notes:

SUMMARY OF THE INVENTION

The present invention comprises an integrated medical monitoring system preferably including at least one local patient monitor, at least one central monitoring system, and at least one remote access device. These components are linked in a network which preferably comprises a wireless RF system. Most preferably, the communications links comprise frequency-hopping, spread spectrum RF communications in the ISM frequency band. However, other wireless communication systems, including IR, may also be used.

The local patient monitor provides sensors for monitoring a number of physiological parameters including but not limited to ECG (electrocardiogram), NIBP (non-invasive blood pressure), SpO.sub.2 via pulse oximetry, respiration, temperature, invasive pressure lines, gas monitoring, and cardiac output. The local patient monitor preferably includes a transceiver, or a transmitter and a receiver, a display and keyboard. The patient monitors can operate independently as a monitoring device, as well as transmit data to and receive monitoring control signals from a central monitoring system. To facilitate entry of data such as patient identity, caregiver identity, pharmaceuticals received, and various other data, the patient monitor preferably includes an electronic data entry device such as a bar code scanner, which can provide coded patient information to transmit to the central monitoring system or a clinical information system, as will be described below.

The central monitoring system comprises a display, a transceiver or a transmitter and a receiver, and memory storage for storing patient data. The central monitoring system receives data from the local patient monitors, displays this information to caregivers at the central monitor, and stores the data for archival and analysis purposes. Preferably, archival records associated with a given patient can be transferred to another central monitoring system or an auxiliary system either through wireless communications or through a hardwired network link between two or more central monitoring systems. A caregiver at the central monitoring system can select among the subset of available waveforms and vital sign data most appropriate for remote display, and this selection is transmitted to the patient monitor. The central monitoring system preferably also includes a scanner for facilitating data entry and retrieval of stored waveforms. The central monitoring system can store timed events, including timed activity charts which show a patient's physiological response versus various activity and exercise levels.

The central monitoring system also monitors incoming data from the patient monitor for medical alert messages, and continually monitors incoming data for possible emergency situations. When an emergency is found, the central monitoring system directly alerts the remote access device through the wireless transceiver. This integrated system eliminates processing and communication steps common in prior art devices. Preferably, the communication link is via a spread-spectrum RF system in the ISM band, thereby providing a high bandwidth transmission with limited extraneous interference, permitting the transfer of continuous waveforms and detailed vital sign information to a remote access device with limited interference.

The remote access device can comprise any of a number of electronic devices including paging systems; personal digital assistants (PDAs); telephones; or laptop, desktop, or other types of computers. Preferably, these devices are fitted with a transceivers to receive data from and transmit data to the wireless communications network described above. Due to the bandwidth of these communications, a significantly higher amount of data can be transmitted than in a standard paging system. Furthermore, because this system does not depend on communications through a standard pager system, problems associated with paging and cellular phone systems, such as busy or temporarily disabled or closed systems which might delay or prevent the receipt of a message, are averted. This is particularly important in applications in which an emergency or alarm signal is sent. Additionally, due to the bi-directional capabilities of the communications link, the sending system can determine that a caregiver has read and responded to a message. The sending system can also verify the availability of memory in a remote access device, and delete unnecessary messages to provide additional space. Therefore, the present invention provides a preferred system for medical alert system critical care monitoring, in that it is able to transmit the message in a timely fashion and verify that it has been delivered and read by an appropriate caregiver.

As noted above, the remote access devices preferably communicate bi-directionally. Due to these bi-directional communication capabilities, a caregiver can obtain updated information from the central monitoring system by requesting data from the remote access device. To facilitate such requests, remote access devices preferably include an electronic data entry device such as a bar code reader so that a caregiver in a remote location may easily scan a bar code to identify a given patient to obtain data. As noted above, the wide bandwidth of the wireless, preferably RF, system allows for a significant amount of data to be transmitted including vital sign statistics and waveforms of various physiological parameters. Because the devices can also communicate with each other, a first caregiver receiving such data in an alarm or other condition can also choose to forward the information to a second caregiver, or forward free-form text to the central monitoring system or the patient monitor itself. Such message may include care instructions or instructions to contact a specialist, thereby allowing a primary physician the opportunity to direct care remotely. Furthermore, although the remote device has been described as part of an overall system, it will be understood that such a device could be operated independently with one or more patient monitors including bi-directional communication capabilities as described above.

The remote access device can alternatively be operated as a medical alert system in which either the patient monitor directly contacts the remote device on discovering an alarm condition or the patient monitor transmits this information to the central monitoring system. The central monitoring system, in turn, transmits the information to the remote access device. The remote access device can include a GPS or other locating system which allows the sending system, whether the patient monitor or the central monitoring system, to determine the location of a plurality of caregivers and select an appropriate primary recipient of the alarm message based on location. The alarm system preferably determines an initial primary recipient based on location, specialty, and/or relationship to the patient (i.e. the patient's primary physician), and then waits for a signal from the remote device indicating that the message has been received and read. Preferably, this signal is sent automatically, although in some cases the recipient may send a coded response such as a password to the system. If a response is not received within a preselected time period, or if the response is negative, the message is sent to one or more secondary recipients. Preferably, the primary device receives a list of secondary recipients and the preselected time frame to forward the message and the primary device notifies the secondary device without further interaction with the sending system. Alternatively, however, this function can be handled by the sending system.

The central monitoring system further comprises a maintenance function which employs the bi-directional communication link between the central monitoring system to verify the available memory space and working status of the remote access devices. The central system can evaluate the data in the remote access device memory and delete unnecessary messages to assure that the device is operational for future data deliveries. Furthermore, upon delivery of data to a remote access device, the central monitoring system can detect when data has been secured and when data has been read. This function is particularly useful in time-sensitive medical emergency situations.

Preferably, the medical monitoring system also comprises at least one auxiliary system for transmitting and receiving clinical data, thereby providing a more complete overall medical monitoring and recordation system. The auxiliary system can be connected to the medical monitoring system via a hardwired network link, or through a wireless communication link. The auxiliary equipment can comprise a diagnostic workstation such as an ECG diagnostic workstation, a clinical information system, or other database system. Diagnostic workstations receive selected archived physiological data such as vital sign data, waveforms, timed cardiac events, or other events from the central monitoring system or a patient monitor for further clinical analysis by a caregiver. Clinical information systems store patient medical records such as demographics, assessments, diagnoses, care plans, notes, physiological waveform data, vital signs, laboratory, and other results, prescription and pharmacy information, insurance and billing information, and other personal patient information. Preferably, the information in the clinical information system is coordinated based on an identification number assigned to a patient when entering the hospital. This number, represented as a bar code, can the be used by the patient monitor and the central monitoring system to simplify the storage, retrieval, and transfer of patient data. Preferably, therefore, all devices through which data is entered, archived or retrieved include a bar code scanner or other electronic entry device.

Other objects, features and advantages of the present invention will be apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings described below wherein like components have like numerals throughout several views.
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While preferred embodiments of the invention have been shown and described, it will be clear to those skilled in the art that various changes and modifications can be made without departing from the invention in its broader aspects as set forth in the claims provided hereinafter.