Communications system and protocol for medical environment

• US 7,751,375 B2
• Filed: 02/22/2007
• Issued: 07/06/2010
• Est. Priority Date: 02/22/2007
• Status: Active Grant

• Current Assignee: Rauland-Borg Corporation (Ametek Incorporated)
• Original Assignee: Rauland-Borg Corporation (Ametek Incorporated)
• Inventors: Garcia, Reuben P., Gallagher, Lawrence W., Perkins, Michael C.
• Primary Examiner(s): Pham; Chi H
• Assistant Examiner(s): Huang; Weibin
• Application Number:
  US11/678,011
• Publication Number:
  US 20080205310A1
• Time in Patent Office: 1,230 Days
• Field of Search: 370/229, 370/235, 370/236, 370/241, 370/242, 370/252, 370/310, 370/328, 370/329, 370/330, 370/336, 370/343, 370/345, 370/431, 370/436, 370/437, 439/557, 439/625, 439/626, 439/660, 439/950
• US Class Current: 370/336
• CPC Class Codes: A61B 2560/0204 of power management
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2562/226 comprising means for identifying the connector, e.g. to prevent incorrect connection to socket
• CPC Class Codes: A61B 2562/227 Sensors with electrical connectors
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/1113 Local tracking of patients, e.g. in a hospital or private home
• CPC Class Codes: A61B 5/6887 mounted on external non-worn devices, e.g. non-medical devices
• CPC Class Codes: A61B 5/6891 Furniture
• CPC Class Codes: A61B 5/6892 Mats
• CPC Class Codes: A61G 12/00 Accommodation for nursing, e.g. in hospitals, not covered by groups A61G1/00 - A61G11/00, e.g. trolleys for transport of medicaments or food service or tea-tables, trolleys or wagons A47B31/00; Prescription lists
• CPC Class Codes: A61G 2203/70 with special adaptations, e.g. for safety or comfort
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A communications system and protocol are described for wirelessly interconnecting a pair of bed and wall units that communicate the patient information, including bed exit alerts, from the patient supporting equipment to the hospital nurse call system. A linking procedure is provided for establishing a communications link to interconnect the pair of units, wherein the communications link fails upon detection of a third communications device simultaneously undergoing the link attempt mode. In one embodiment, the system provides for advanced collision detection by monitoring corruption of the end-of-packet byte within the periodic check-in message sequences between the linked units to prevent data corruption and future collisions. To ensure prompt interconnection of units, embodiments of the invention provide for a link reminder to alert the health care provider to initiate the steps for linking the bed and wall units whenever two or more unlinked units are in proximity.

Claims

1. A method for maintaining a wireless communications link between a mobile unit gathering patient information and a stationary unit for processing the patient information, the method comprising:

repeatedly transmitting link status messages between the mobile and stationary units, each link status message occupying a nominal time slot and comprising one or more data fields for relaying the patient information between the mobile and stationary units and a collision indicator field for indicating a link status message collision;

providing an early indication of an onset of collisions of the link status messages transmitted by the mobile and stationary units with link status messages transmitted by another mobile and stationary unit pair by monitoring corruption of the collision indicator field, wherein the early indication of collisions comprises detecting the corruption of the collision indicator field prior to corruption of the data fields in the nominal time slot; and

shifting subsequent transmissions of the link status messages when a collision is detected.

2. The method of claim 1 further comprising one of shifting a time reference of the subsequent transmissions of the link status messages and transmitting the link status messages on another operating channel when the collision is detected.

3. The method of claim 1 further comprising retrying the transmission of the link status messages on another operating channel when the wireless communications link is impaired due to a degradation in signal conditions.

4. The method of claim 1 further comprising routing the link status messages based on unique identifiers corresponding to each of the mobile and stationary units.

5. The method of claim 1 wherein the wireless communications link supports a message format for relaying the patient information to a hospital communications network and the link status messages include full frame transmissions according to the message format.

6. The method of claim 1 wherein the patient information includes at least one of a bed occupancy status signal, a nurse call signal, a nurse call assurance signal, a wireless communications link status signal, and an operating status signal associated with at least one of the units.

7. A method for maintaining wireless communications links, each link communicating patient information between a portable device attached to a portable hospital resource and a stationary device, the method comprising:

repeatedly transmitting link status messages over two or more of the wireless communications links, where the transmissions by each link are periodic;

providing an early indication of an onset of a collision between the two or more wireless communications links transmitting the link status messages, wherein the early indication of an onset of a collision comprises detecting a partial temporal overlap of the link status messages of the two or more wireless communications links prior to data corruption in the link status messages; and

shifting the repetition of the periodic link status messages in at least one of the wireless communications links when the collision is detected.

8. The method of claim 7 further comprising one of shifting a time reference of the repetition of the periodic link status messages and transmitting the link status messages on another operating channel when the collision is detected.

9. The method of claim 7 wherein the collision is detected by monitoring a collision indicator field in the link status messages.

10. The method of claim 7 further comprising retrying the transmission of the link status messages on another operating channel for at least one of the wireless communications links when the at least one wireless communications link is impaired due to a degradation in signal conditions.

11. The method of claim 7 wherein the wireless communications links support a message format for relaying the patient information to a hospital communications network and the link status messages include full frame transmissions according to the message format.

12. The method of claim 7 wherein the patient information includes at least one of an occupancy status signal associated with the portable hospital resource, a nurse call signal, a nurse call assurance signal, a wireless communications link status signal, and an operating status signal associated with at least one of the devices.

33. The method of claim 7 wherein the partial temporal overlap is indicated by corruption of a collision indicator field of the link status messages when data fields of the link status messages remain uncorrupted subsequent to the collision.

13. A system for maintaining a wireless communications link between a mobile hospital bed and a hospital communications network, the system comprising:

a first pair of transceivers supporting a wireless communications link between the mobile hospital bed and the hospital communications network;

one of the transceivers including an interface that enables the transceiver to function as a node of the hospital communications network; and

the other transceiver including circuitry for (1) repeatedly transmitting to the one transceiver link status messages, (2) providing an early indication of an onset of a collision of at least one of the link status messages with other communication links, wherein the early indication of the collision comprises detecting a partial temporal overlap of the link status messages of the first pair of transceivers with link status messages of a second pair of transceivers prior to data corruption in the link status messages of the first pair of transceivers, and (3) shifting transmissions of the link status messages in at least the first pair of transceivers subsequent to detection of the collision.

14. The system of claim 13 wherein the other transceiver further includes circuitry for one of shifting a time reference of the transmissions of the link status messages and transmitting the link status messages on another operating channel when the collision is detected.

15. The system of claim 13 wherein the collision is detected by monitoring a collision indicator field in the link status messages.

16. The system of claim 13 wherein the other transceiver further includes circuitry for retrying the transmission of the link status messages on another operating channel when the wireless communications link is impaired due to a degradation in signal conditions.

17. The system of claim 13 wherein the transceivers route the link status messages based on a unique identifier corresponding to each transceiver.

18. The system of claim 13 wherein the wireless communications link supports a message format for relaying the patient information to the hospital communications network and the link status messages include full frame transmissions according to the message format.

19. The system of claim 13 wherein the wireless communications link relays patient information to the hospital communications network, the patient information including at least one of a patient occupancy status signal associated with the mobile hospital bed, a nurse call signal, a call assurance signal, and a system status signal associated with at least one of the transceivers.

34. The system of claim 13 wherein the partial temporal overlap is indicated by corruption of a collision indicator field of the link status messages in the first pair of transceivers when data fields of the link status messages in the first pair of transceivers remain uncorrupted subsequent to the collision.

20. A mobile medical communications device for relaying patient information via a wireless communications link to a stationary site, the device comprising:

a transceiver for establishing a wireless communications link to the stationary site, where the wireless communications link supports a message format for relaying patient information to the stationary site;

a controller in communication with the transceiver and a source of patient information for (1) causing the transceiver to repeatedly transmit link status messages to the stationary site, thereby checking an integrity of the wireless communications link, and (2) shifting the repeatedly transmitted link status messages upon detection of a partial temporal overlap of the link status messages with link status messages associated with another mobile medical communications device and stationary site pair prior to data corruption in the link status messages of the mobile medical communications device; and

a housing for the transceiver and the controller.

21. The mobile medical communications device of claim 20 wherein the controller causes the transceiver one of to shift a time reference of the transmissions of the link status messages and to transmit the link status messages on another operating channel when the collision is detected.

22. The mobile medical communications device of claim 20 wherein the partial temporal overlap is detected by monitoring a collision indicator field in the link status messages.

23. The mobile medical communications device of claim 20 wherein the controller causes the transceiver to retry the transmission of the link status messages on another operating channel when the wireless communications link is impaired due to a degradation in signal conditions.

24. The mobile medical communications device of claim 20 wherein the link status messages are routed between the mobile medical communications device and the stationary site based on their respective unique identifiers.

25. The mobile medical communications device of claim 20 wherein the link status messages include full frame transmissions according to the message format.

26. The mobile medical communications device of claim 20 wherein the patient information includes at least one of a patient occupancy status signal associated with the portable hospital resource, a nurse call signal, a call assurance signal, and a system status signal associated with at least one of the mobile medical communications device and the stationary site.

35. The mobile medical communications device of claim 20 wherein the partial temporal overlap is indicated by corruption of a collision indicator field of the link status messages when data fields of the link status messages transmitted by the transceiver remain uncorrupted subsequent to a collision due to the partial temporal overlap.

27. A stationary medical communications device for receiving patient information from a mobile telecommunications device attached to a portable hospital resource, the stationary medical communications device comprising:

a transceiver establishing a wireless communications link with the mobile telecommunications device; and

a controller in communication with the transceiver for detecting corruption of one or more link status messages repeatedly transmitted by the mobile telecommunications device, and providing an indication that subsequent transmissions of the link status messages should be shifted to avoid future corruption, wherein the indication is associated with an early onset of a collision of the one or more link status messages due to a partial temporal overlap with link status messages associated with another mobile and stationary device pair prior to data corruption in the link status messages transmitted by the mobile telecommunications device.

28. The stationary medical communications device of claim 27 wherein in response to the indication the mobile telecommunications device changes one of a time reference and an operating channel of the subsequent transmissions of the link status messages.

29. The stationary medical communications device of claim 27 wherein the controller provides a further indication to retry the transmission of the link status messages on another operating channel when the wireless communications link is impaired due to a degradation in signal conditions.

30. The stationary medical communications device of claim 27 wherein the link status messages are routed between the stationary medical communications device and the mobile telecommunications device based on their respective unique identifiers.

31. The stationary medical communications device of claim 27 wherein the wireless communications link supports a message format for relaying the patient information to a hospital communications network and the link status messages include full frame transmissions according to the message format.

32. The stationary medical communications device of claim 27 wherein the patient information includes at least one of a patient occupancy status signal associated with the portable hospital resource, a nurse call signal, a call assurance signal, and a system status signal associated with at least one of the mobile telecommunications device and the stationary medical communications device.

36. The stationary medical communications device of claim 27 wherein the partial temporal overlap is indicated by corruption of a collision indicator field of the link status messages when data fields of the link status messages transmitted by the mobile telecommunications device remain uncorrupted subsequent to the collision.