Automatic speech recognition in vitreo-retinal surgery. A project for a prototypal computer-based voice-controlled vitrectomy machine.

In the past half decade automatic speech recognition techniques, software and hardware technology have matured enough to support sophisticated medical applications. The project described aimed at introducing a computer-based, voice-controlled prototype system in a simulated vitreo-retinal surgery scenario. The aim was to provide the surgeon with a tool that could significantly improve the quality and ease of work and shorten the duration of intervention. The speech recognition system allows voice entry of simple commands to simulate surgical instrument control, including the infusion pump, vitreous cutter and diathermy. The project relies on a Markov-based, speaker-dependent, commercial isolated-word recognizer, and consists of a specific recognition vocabulary and application software, created and developed by the authors. Results have been encouraging. The system performed well under the test conditions, proving robust, simple to use and accurate (over 97% average word recognition rate). On the basis of their experience, the authors believe that automatic speech recognition technology, though suffering from some limitations such as the need for training, speaker dependence and a relatively small vocabulary, and requiring extensive testing under operating conditions, merits further development and opens new perspectives for a possible new generation of surgical instruments.

Automated measurement of strabismic deviation.

A new computerized method of performing automated measurements of the angle of strabismus is presented, based on an infrared television camera, an image analyzer, and a commercial computer. This automated system provides a strategy of examination for patients in whom strabismus is suspected and makes possible a qualitative and quantitative diagnosis of the type of strabismus. In the case of a paralytic deviation, the involved muscle can also be identified with this instrument. The raw data from the image processor are saved and enhanced digitally. The image can be retrieved via monitor or printer, and data can be saved on mass memory. With this instrument, it is possible to follow various diagnostic procedures for strabismus step-by-step and to answer the following questions: is strabismus present? Is it convergent, divergent, or vertical strabismus? What is the angle of deviation? Which is the paralytic or paretic muscle in the case of incomitant deviation?

Vergence movements in comitant strabismus.

Vergence movements induced by base-out prisms were recorded, with an infrared eye tracker, for 6 patients with comitant esotropia (i.e., convergent strabismus) and anomalous retinal correspondence and for 6 normal subjects. Vergence movements of strabismic subjects were much slower and showed characteristics different from those of controls. It may be argued that vergence movements are induced by disparity and represent the motor fusion component left over in strabismus. In fact, in this study accommodative as well as proximal vergence had been ruled out. Therefore, the movements recorded can be considered the objective representation of the well-known phenomenon of prism compensation or adaptation, found in many strabismic patients.

A new automatic computerized deviometer.

An automatized computerized deviometer is presented based on an infrared TV camera, an image analyzer and a computer. With this instrument it is possible to follow step-by-step the various diagnostic procedures in strabismus and to answer the following questions: is there a strabismus? is it convergent, divergent or vertical strabismus? what is the angle of deviation? which is the paralytic or paretic muscle in the case of incomitant strabismus?

Vitrectomy, scleral buckling, and peripheral diathermy treatment for severe proliferative vitreoretinopathy.

Transvitreal diathermy was combined with vitrectomy, scleral buckling, and silicone oil injection to treat 28 eyes with severe proliferative vitreoretinopathy and fore-shortened peripheral retina. A special gold tip on the diathermy probe prevented adhesions to the retina. The probe can be used for coaxial bipolar diathermy or for internal-external bipolar diathermy when combined with an electrode on the external scleral surface. Nineteen (68%) of 28 eyes treated with these methods achieved anatomic success and 10 eyes obtained final visual acuity ranging from 5/200 to 20/70.