Mechanisms and methods with variable counterbalance to control movement and force of a head of a medical system at an anatomical site

A medical system comprising:

• a head having an end arranged to face a reference plane;
• and
• a multistage slide mechanism coupled with the head and comprising:
• a coarse-float mechanism configured to enable movement of the head relative to the reference plane, and
• a fine-float mechanism configured to limit a force applied through the head to an initial force, and to reduce the force applied through the head to a reduced force less than the initial force in response to a presence of a first triggering event, the fine-float mechanism comprising a fine-float counterbalance mechanism configured to counterbalance a weight of a load mass comprising the head to limit the force applied through the head to the initial force, and counterbalance a weight of the load mass comprising the head to limit the force applied through the head to the reduced force, in response to a presence of the first triggering event;
• and
• a first detection mechanism configured to detect a presence of or an absence of the first triggering event.

A control system for controlling a fine-float counterbalance mechanism of a medical system having a head, a cone attachment mechanism configured to secure the head to a patient interface, and an eye attachment mechanism configured to secure the patient interface to an anatomical site, the fine-float counterbalance mechanism configured to set an apparent weight of a load mass comprising the head to either of a heavy weight and a light weight, the control system comprising:

• a set of sensors including one or more of:
• a displacement sensor configured to provide sensor signals indicative of movement of the head through a fine-float mechanism,
• a cone attachment sensor configured to provide a sensor signal indicative of a coupling between the head and the patient interface, and
• an eye attachment sensor configured to provide a sensor signal indicative of a coupling between the patient interface and the anatomical site,
• a set of operator controls configured to provide control signals indicative of a brake release;
• and
• a controller coupled to the set of sensors and the set of operator controls, and comprising a variable force module configured to set the apparent weight of the load mass to either of the heavy weight and the light weight based on one or more of the sensor signals from the displacement sensor, the sensor signals from the cone attachment sensor, the sensor signals from the eye attachment sensor, and the control signals from the set of operator controls.