# US 10,441,210 B2 · Method of normalizing implant strain readings to assess bone healing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,441,210 B2 - Document ID: US10441210B2 - Status: Granted - Kind: B2 - Application number: 12/909,220 - Filed: 2010-10-21 - Published: 2011-04-28 - Granted: 2019-10-15 - Earliest claimed: 2009-10-21 - Assignees: DePuy Synthes Products, Inc. - Applicants: Carl Deirmengian; George Mikhail; Glen Pierson - Inventors: Carl Deirmengian; George Mikhail; Glen Pierson - Web page: https://patentgrep.com/patent/US10441210B2 ## CPC - A61B 5/4504: {Bones (A61B5/4547 takes precedence)} - A61B 5/076: {Permanent implantation} - A61B 5/103: Measuring devices for testing the shape, pattern, {colour,} size or movement of the body or parts thereof, for diagnostic purposes (measuring instruments specially adapted for dentistry A61C19/04) - A61B 5/686: {Permanently implanted devices, e.g. pacemakers, other stimulators, biochips (A61B5/6861 takes precedence)} - A61B 17/80: Cortical plates {, i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates} - A61F 2/4657: {Measuring instruments used for implanting artificial joints (for surgical instruments A61B90/06)} - A61B 17/8625: {Shanks, i.e. parts contacting bone tissue} - A61B 2017/00221: {with wireless transmission of data, e.g. by infrared radiation or radiowaves} - A61B 2090/064: {for measuring force, pressure or mechanical tension} - A61B 2562/0261: Strain gauges - A61B 2562/028: Microscale sensors, e.g. electromechanical sensors [MEMS] - A61B 2562/166: the sensor is mounted on a specially adapted printed circuit board - A61F 2002/4666: {for measuring force, pressure or mechanical tension} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract A device for treating bone in a living body includes (a) comprises an implant configured for attachment to a bone; (b) a first sensor measuring a strain on a first portion of the implant, the first portion of the implant being configured to be mechanically coupled to a weakened portion of a bone when the implant is coupled to the bone in a target position in combination; and (c) a second sensor measuring strain in a non-weakened portion of the bone. ## Claims ### Claim 1 A device for treating bone in a living body, comprising: an implant configured for attachment to an exterior of a bone; a first sensor measuring a strain on a first portion of the implant, the first portion of the implant being configured to be mechanically coupled to a weakened portion of a bone when the implant is coupled to the bone in a target position; and a second sensor isolated between two bone fixation element receiving holes of the implant measuring strain in a non-weakened portion of the bone. ### Claim 2 (depends on 1) The device of claim 1, wherein the implant is a plate configured to be coupled to a bone overlying a fracture site. ### Claim 3 (depends on 2) The device of claim 2, wherein the second sensor is configured for placement in a shoe to measure the load on a leg including the bone simultaneously with a measurement of strain across the fracture site from the first sensor. ### Claim 4 (depends on 1) The device of claim 1, wherein the second sensor is configured to be coupled directly to the non-weakened portion of the bone. ### Claim 5 (depends on 1) The device of claim 1, further comprising: a third sensor mounted to a portion of a bone fixation element which, when in an operative position, is inserted into the non-weakened portion of the bone so that the third sensor contacts a cortical wall of the non-weakened portion of the bone. ### Claim 6 (depends on 5) The device of claim 5, wherein the third sensor extends about a circumference of a proximal portion of the bone fixation element. ### Claim 7 (depends on 1) The device of claim 1, wherein the implant includes a rigid portion and a flexible portion having a first bending stiffness less than a second bending stiffness of the rigid portion, the second sensor being mounted on the flexible portion. ### Claim 8 (depends on 1) The device of claim 1, wherein the second sensor is a load sensor measuring a load on the bone. ### Claim 9 (depends on 1) The device of claim 1, wherein the first and second sensors provide data to an external data gathering unit wirelessly. ### Claim 10 (depends on 9) The device of claim 9, wherein the first and second sensors are one of MEMs sensors and powered chips connected to printed circuit boards. ### Claim 11 A system for tracking a bone healing progress, comprising: an implant fixing a fracture of a bone including a first sensor measuring strain mounted thereon at a position which, when the implant is mounted on an exterior of the bone in a target position, is mechanically coupled to a fracture of the bone; and a second sensor isolated between two bone fixation element receiving holes of the implant measuring strain on a portion of the bone separated from the fracture such that a ratio of the first strain to the second strain normalizes an effect of loads on the bone and indicates an increased stiffness as the fracture heals. ### Claim 12 (depends on 11) The system of claim 11, further comprising: a bone fixation element, a third sensor being mounted at a proximal end thereof so that, when the bone fixation element is inserted into the bone to a desired position, the third sensor contacts a cortical wall of the bone. ### Claim 13 (depends on 11) The system of claim 11, wherein the implant includes a flexible portion and a rigid portion, a first bending stiffness of the rigid portion being greater than a second bending stiffness of the flexible portion, the second sensor being mounted on the flexible portion while the first sensor is mounted on the rigid portion. ### Claim 14 (depends on 13) The system of claim 13, further comprising: first and second locking screws which, when the implant is coupled to the bone in a target configuration, are inserted through the two bone fixation element receiving holes on opposing sides of the flexible portion. ### Claim 15 A method, comprising: measuring strain on a first portion of an implant via a first sensor which, when the implant is coupled to a bone in a desired configuration, is mechanically coupled to a fracture of the bone, the implant being attached to an exterior of a bone; measuring a second strain spaced from the fracture in a non-weakened portion of the bone via a second sensor isolated between two bone fixation element receiving holes of the implant; and determining a ratio of the strain measured by the first sensor to the strain measured by the second sensor to normalize an effect of loads on the bone. ### Claim 16 (depends on 15) The method of claim 15, wherein the second sensor is mounted on a second portion of the implant which, when the implant is coupled to the bone in the desired configuration, is spaced from the fracture on a solid portion of the bone. ### Claim 17 (depends on 15) The method of claim 15, further comprising: mounting a further sensor on a solid portion of the bone, outside a perimeter of the implant. ### Claim 18 (depends on 15) The method of claim 15, further comprising: inserting a bone fixation element into a solid portion of the bone, a third sensor extending about a circumference of a proximal portion of the bone fixation element such that, when the bone fixation element is inserted into the bone, the third sensor contacts a cortical wall of the bone to measure deformation thereof. ### Claim 19 (depends on 15) The method of claim 15, wherein the strain measurements from the first and second sensors are obtained wirelessly by a device which remains external to the body. ### Claim 20 (depends on 19) The method of claim 19, wherein the first and second sensors are one of MEMs sensors and powered chips connected to printed circuit boards.