EP-4734865-A1 - FAILURE DETECTION AND SENSOR BASED CONTROL IN A MOTORIZED BONE FIXATION DEVICE

Abstract

A control system for use with an adjustable bone fixation device having a frame connectible to bone tissue and a plurality of struts connected to the frame, the control system comprising: a plurality of actuators associated with the plurality of struts, each actuator configured for adjusting a length of at least one strut; and circuitry configured to: signal the plurality of actuators to adjust the struts according to a predefined actuation plan which sets operational parameters and permitted ranges thereof; determine a situation of potential failure associated with at least one actuator and involving at least one of the operational parameters being out of the permitted range; and implement, by signaling the at least one actuator, a recovery protocol designed to attempt completion of strut adjustment according to the predefined actuation plan.

Inventors

• HARARI, SHAHAR
• COHEN, OREN
• LAVORITANO, Scott P.
• MONTELLO, ALBERT A.

Assignees

• Synthes GmbH

Dates

Publication Date

20260506

Application Date

20240628

Claims (20)

1. 1. A control system for use with an adjustable bone fixation device having a frame connectible to bone tissue and a plurality of struts connected to the frame, the control system comprising: a plurality of actuators associated with the plurality of struts, each actuator configured for adjusting a length of at least one strut; and circuitry configured to: signal the plurality of actuators to adjust the struts according to a predefined actuation plan which sets operational parameters and permitted ranges thereof; determine a situation of potential failure associated with at least one actuator and involving at least one of said operational parameters being out of the permitted range; and implement, by signaling the at least one actuator, a recovery protocol designed to attempt completion of strut adjustment according to the predefined actuation plan.
2. 2. The control system according to claim 1, wherein the predefined actuation plan sets permitted ranges for one or more of the following operational parameters or indicators thereof: A. timing of adjustment; B. an adjustment duration; C. torque to be applied by the actuator onto the strut; D. a desired adjustment in the length of a strut.
3. 3. The control system according to claim 1 or claim 2, wherein the circuitry is configured to select the recovery protocol from a plurality of recovery protocols stored in a memory of said control system.
4. 4. The control system according to any one of the preceding claims, wherein the recovery protocol is designed to prevent or at least delay the control system from entering a final system error mode in which all actuators are stopped.
5. 5. The control system according to any one of the preceding claims, wherein the plurality of recovery protocols include one or more of the following protocols or a combination thereof: (protocol a) waiting a preset time period, and re-attempting adjustment of the strut; (protocol b) moving the strut in a reciprocating motion along a predefined distance; (protocol c) re-attempting the adjustment that was not carried out or was only partially carried out in one or more successive actuation sessions.
6. 6. The control system according to any one of claims 2-5, wherein the control system comprises one or more sensors configured for measuring said operational parameters or indicators thereof.
7. 7. The control system according to any one of the preceding claims, wherein the circuitry comprises one or more sensors configured for sensing conditions that are associated with one or both of the device and its surroundings, the one or more sensors including: a temperature sensor; a humidity sensor; a sensor configured for detecting the current posture of the patient; a sensor configured for detecting a current orientation of the body part to which the device is connected; an acceleration sensor; a weight/ load sensor; and wherein the circuitry is configured to check, upon entering a treatment mode, whether the conditions sensed by the one or more sensors are within a permitted range.
8. 8. The control system according to claim 7 when dependent on claim 5, wherein the plurality of recovery protocols further include (protocol d): delaying adjustment of the strut and re-attempting it when at least one of: (a) the one or more sensors detect a desired change in at least one of the conditions; (b) the conditions sensed by all of said one or more sensors are within a permitted range.
9. 9. The control system according to any one of claims 5-8, where in the circuitry is configured to implement more than one recovery protocol, and to stop when either adjustment of the strut is completed or a predefined time period passed.
10. 10. The control system according to any one of the preceding claims, wherein the circuitry is configured to identify whether the potential failure is associated with a single actuator or is associated with multiple actuators.
11. 11. The control system according to claim 10, wherein if the potential failure is associated with a single actuator, the circuitry controls operation of the plurality of actuators according to one or more of the following: (A) continue operation of all actuators except for the actuator for which potential failure had been indicated; (B) carry out the recovery protocol for the actuator for which potential failure had been indicated, and only then continue operation of all actuators;(C) stop operation of all actuators.
12. 12. The control system according to any one of the preceding claims, wherein the circuitry is configured to one or both of suggest and effect changes in the actuation plan for compensating for a recovery protocol which involves a delay in strut adjustment.
13. 13. An adjustable bone fixation device, comprising: a frame connectible at least indirectly to bone tissue and comprising at least two spaced apart portions; a plurality of struts extending between the at least two portions of the frame; and the control system according to claim 1, whereby the plurality of actuators are operably connected to the plurality of struts.
14. 14. A control system for use with an adjustable bone fixation device having a frame connectible to bone tissue and a plurality of struts connected to the frame, the control system comprising: a plurality of actuators associated with the plurality of struts, each actuator configured for adjusting a length of at least one strut; a plurality of sensors configured for sensing one or more of the following conditions: pressure, temperature, load, acceleration; and circuitry configured to: receive indications from the one or more sensors regarding the sensed conditions; determine whether the sensed conditions are within their permitted range; if at least one of the sensed conditions is outside its permitted range, delay or retry adjustment of the struts; when all sensed conditions are within their permitted range, automatically activate the plurality of actuators to adjust the struts.
15. 15. The control system according to claim 14, wherein if at least one of the sensed conditions is outside its permitted range, the circuitry is configured to issue one or both of: an alert regarding the sensed condition, instructions to the patient or caregiver.
16. 16. The control system according to claim 14 or claim 15, wherein when all sensed conditions are within their permitted range, the circuitry is configured to signal the plurality of actuators to adjust the struts according to a predefined actuation plan which sets operational parameters for the actuators and permitted ranges thereof.
17. 17. The control system according to any one of claims 14-16, wherein the circuitry is configured to one or both of suggest and effect changes in the predefined actuation plan to compensate for the delayed adjustment.
18. 18. The control system according to any one of claims 14-17, wherein the circuitry is further configured to: determine a situation of potential failure associated with at least one actuator and involving at least one of said operational parameters being out of the permitted range; and implement, by signaling the at least one actuator, a recovery protocol designed to attempt completion of strut adjustment according to the predefined actuation plan.
19. 19. A control system for use with an adjustable bone fixation device having a frame connectible to bone tissue and a plurality of struts connected to the frame, the control system comprising: a plurality of actuators associated with the plurality of struts, each actuator configured for adjusting a length of at least one strut; a control unit comprising circuitry configured to signal the plurality of actuators to adjust the struts; the control unit having a selectively permeable housing which allows air to flow through; and at least one pressure sensor located inside the housing; wherein the circuitry is configured to receive indications from the at least one pressure sensor to determine whether the pressure is within a permitted range.
20. 20. The control system according to claim 19, wherein if the pressure is outside its permitted range, the circuitry is configured to delay adjustment of the struts until the pressure is within the permitted range.

Description

FAILURE DETECTION AND SENSOR BASED CONTROL IN A MOTORIZED BONE FIXATION DEVICE TECHNOLOGICAL FIELD [0001] This invention relates to controlled operation of an adjustable motorized bone fixation device, and more particularly to sensor-based control and automated detection of failure or potential failure in the device. BACKGROUND [0002] WO2022024133A8 discloses “A kit, including: a strut of a bone fixation device including a fixed portion and an extending portion, wherein the strut comprises a linear actuator mechanically connected to the extending portion; at least one motor adaptor coupled to the linear actuator, wherein the motor adaptor comprises a motor fastener; at least one motor unit selectively attachable and detachable from the motor fastener, wherein the motor unit is configured to functionally couple to the linear actuator and axially extend the extending portion of the strut; wherein the motor fastener is shaped and sized to receive a portion of the motor unit.” [0003] US11076801 discloses “An electrical circuitry fitted to be connected or to be an integral part of a bone fixation device having at least one linear actuator coupled between two rings, including: at least one linear actuator connector, mechanically and/or electrically connectable to said at least one linear actuator; a control circuitry, wherein said control circuitry measures a value related to the movement of said at least one linear actuator and/or to the distance or change in distance between said two rings, by receiving signals from said linear actuator connector; and a memory, wherein said memory stores said value.” GENERAL DESCRIPTION Example 1 A control system for use with an adjustable bone fixation device having a frame connectible to bone tissue and a plurality of struts connected to the frame, the control system comprising: a plurality of actuators associated with the plurality of struts, each actuator configured for adjusting a length of at least one strut; and circuitry configured to: signal the plurality of actuators to adjust the struts according to a predefined actuation plan which sets operational parameters and permitted ranges thereof; determine a situation of potential failure associated with at least one actuator and involving at least one of said operational parameters being out of the permitted range; and implement, by signaling the at least one actuator, a recovery protocol designed to attempt completion of strut adjustment according to the predefined actuation plan. Example 2 The control system according to Example 1, wherein the predefined actuation plan sets permitted ranges for one or more of the following operational parameters or indicators thereof: A. timing of adjustment; B. an adjustment duration; C. torque to be applied by the actuator onto the strut; D. a desired adjustment in the length of a strut. Example 3 The control system according to Examples 1 or 2, wherein the circuitry is configured to select the recovery protocol from a plurality of recovery protocols stored in a memory of said control system. Example 4 The control system according to Example 1, wherein the circuitry selects the recovery protocol from the plurality of recovery protocols based on one or both of: the type of operational parameter that is out of the permitted range, and the extent in which the parameter exceeds the permitted range. Example 5 The control system according to any one of the preceding Examples, wherein the recovery protocol is designed to prevent or at least delay the control system from entering a final system error mode in which all actuators are stopped. Example 6 The control system according to any one of Examples 3-5, wherein the plurality of recovery protocols include one or more of the following protocols or a combination thereof: (protocol a) waiting a preset time period, and re-attempting adjustment of the strut; (protocol b) moving the strut in a reciprocating motion along a predefined distance; (protocol c) re-attempting the adjustment that was not carried out or was only partially carried out in one or more successive actuation sessions. Example 7 The control system according to any one of Examples 2-6, wherein the control system comprises one or more sensors configured for measuring said operational parameters or indicators thereof. Example 8 The control system according to any one of Examples 2-7, wherein the operational parameters include parameter (C), and wherein the at least one parameter indicative of torque comprises: consumption of electrical current by the at least one actuator; operating voltage of the at least one actuator, rotation speed of the at least one actuator. Example 9 The control system according to any one of Examples 2-8, wherein the operational parameters include parameter (D), and, wherein each actuator is associated with an encoder and the circuitry is configured to determine the change in length of the strut based on data received from the encoder. Example 10 The c