METHOD AND DEVICE FOR CUP IMPLANTING USING INERTIAL SENSORS

• US 20160220318A1
• Filed: 02/02/2016
• Published: 08/04/2016
• Est. Priority Date: 02/02/2015
• Status: Active Grant

• Current Assignee: ORTHOsoft ULC. (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Orthosoft Inc. (Zimmer Biomet Holdings, Inc.)
• Inventors: Falardeau, Bruno, Duval, Karine, Leone, Yvan, Paradis, Francois, Li, Di, Valin, Myriam, Pelletier, Benoit, Moreau-Belanger, Laurence
• Granted Patent: US 10,881,470 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61B 17/1666 for the acetabulum
• CPC Class Codes: A61B 2034/2048 using an accelerometer or inertia sensor
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery

Abstract

A computer-assisted surgery (CAS) system comprises a cup implanting device including a shaft having a tooling end and a handle end with a handle for being manipulated, the shaft having a longitudinal axis, the tooling end adapted to support a cup for being received in an acetabulum of a patient, and a rotation indicator having a visual guide representative of a device plane, wherein the device plane is in a known position and orientation relative to a center of the cup on the tooling end. A CAS processing unit includes at least one inertial sensor unit connected to the cup implanting device, the inertial sensor unit outputting three-axes readings and having a virtual preset orientation related to a reference axis of a pelvis of the patient, the virtual preset orientation being based on pre-operative imaging specific to the pelvis of the patient, the reference axis of the pelvis passing through a center of rotation of said acetabulum of the pelvis and through a reference landmark of the pelvis, wherein an instant three-axis orientation of the longitudinal axis of the cup implanting device is trigonometrically known relatively to the reference axis when the cup is in the acetabulum of the patient and the device plane passes through the reference landmark via the visual guide, the instant three-axis orientation used for calibrating the inertial sensor unit on the cup implanting device relative to the pelvis.

Claims

1. A computer-assisted surgery (CAS) system comprising:

a cup implanting device including

a shaft having a tooling end and a handle end with a handle for being manipulated, the shaft having a longitudinal axis, the tooling end adapted to support a cup for being received in an acetabulum of a patient, and

a rotation indicator having a visual guide representative of a device plane,

wherein the device plane is in a known position and orientation relative to a center of the cup on the tooling end; and

a CAS processing unit including at least one inertial sensor unit connected to the cup implanting device, the inertial sensor unit outputting three-axes readings and having a virtual preset orientation related to a reference axis of a pelvis of the patient, the virtual preset orientation being based on pre-operative imaging specific to the pelvis of the patient, the reference axis of the pelvis passing through a center of rotation of said acetabulum of the pelvis and through a reference landmark of the pelvis, wherein an instant three-axis orientation of the longitudinal axis of the cup implanting device is trigonometrically known relatively to the reference axis when the cup is in the acetabulum of the patient and the device plane passes through the reference landmark via the visual guide, the instant three-axis orientation used for calibrating the inertial sensor unit on the cup implanting device relative to the pelvis.

2. The CAS system according to claim 1, wherein the center of the cup on the tooling end, the longitudinal axis and the visual guide commonly lie in the device plane, and wherein the instant three-axis orientation of the longitudinal axis of the cup implanting device is known relatively to the reference axis when the cup is in the acetabulum of the patient and the device plane passes through the reference axis via the visual guide.

3. The CAS system according to claim 1, wherein the visual guide is a light source and the device plane is a planar light beam.

4. The CAS system according to claim 1, further comprising a receptacle in the body for releasably receiving the inertial sensor unit.

5. The CAS system according to claim 1, wherein the preset virtual orientation of the inertial sensor unit comprises the reference axis passing through an anterior-superior iliac spine as the reference landmark.

6. The CAS system according to claim 1, comprising two of said at least one inertial sensor unit, one of said inertial sensor unit being connected to the cup implanting device, another one of said inertial sensor unit incorporated in a pelvic reference adapted to be fixed to the pelvis of the patient, for tracking the reference axis during movements of the pelvis.

7. The CAS system according to claim 1, wherein the inertial sensor unit includes a virtual pelvic orientation representative of a current operative condition.

8. The CAS system according to claim 7, wherein the virtual pelvic orientation comprises a tilt of a medio-lateral axis of the patient.

9. The CAS system according to claim 1, wherein the virtual preset orientation is for the patient being in supine decubitus.

10. A method for determining an orientation of a cup implanting device relative to a pelvis, with an inertial sensor unit in computer-assisted surgery comprising:

obtaining a virtual preset orientation based on pre-operative imaging specific to a pelvis of a patient, the virtual preset orientation being related to a reference axis of a pelvis of the patient, the reference axis including a center of rotation of the acetabulum and a reference landmark;

with a cup at an end of the cup implanting device in the acetabulum of the patient, obtaining orientation readings about two axes for the cup implanting device, relative to the pelvis, from the inertial sensor unit;

with a device plane of the cup implanting device visually aligned with the reference landmark, determining an instant position of the device plane relative to the pelvis by using a geometric relation of the device plane relative to the cup implanting device and the orientation readings;

trigonometrically calculating an instant three-axis orientation of the cup implanting device relative to the pelvis, using the instant position of the device plane; and

calibrating the inertial sensor unit on the cup implanting device relative to the pelvis using the instant three-axis orientation.

11. The method according to claim 10, further comprising obtaining an orientation of the medio-lateral axis of the patient, and wherein determining the instant position comprises.

12. The method according to claim 11, wherein obtaining an orientation of the medio-lateral axis of the patient comprises obtaining the orientation from an inertial sensor unit secured to the pelvis.

13. The method according to claim 11, wherein obtaining an orientation of the medio-lateral axis of the patient comprises obtaining the orientation from manipulations performed with the inertial sensor unit prior to being attached to the cup implanting device.

14. The method according to claim 10, further comprising tracking the orientation of the cup implanting device in three degrees of freedom relative to the pelvis.

15. The method according to claim 14, wherein tracking the orientation of the cup implanting device relative to the pelvis comprises outputting an anteversion and an inclination of the cup.

16. The method according to claim 10, wherein the virtual preset orientation is for the patient being in supine decubitus, and further wherein obtaining orientation readings about two axes for the cup implanting device, relative to the pelvis, from the inertial sensor unit comprises obtaining orientation readings representative to an angle between a longitudinal axis of the cup implanting device and a ground plane, and representative of a rotation of the cup implanting device about its longitudinal axis.